Tina, I made a similar move (Lawrence KS to Jacksonville FL) in late fall with orchids, a wife, and two small boys, and can make some suggestions that may be helpful for you, but I need lots more information. Where in Montana is your starting point, and where in NM is your destination? I don't have a map that shows Rio Rancho. Will you be alone, or with someone who can spell you driving? Will there be other stuff in the trailer, or just the plants? Will you have a heated location to load and unload the U-Haul? Give me as much detail about your plans as you can, and I will respond as soon as I hear from you.

I wish I had someone to offer suggestions for my trip, but we made it just fine.

Bill

Helena Montana to actually Jemez Springs NM in late January, they will hauled by me in a uhaul trailer, I made a similar trip from Houston to Helena a couple of years ago, and they all froze, and lost everything, hoping to avoid that.

they will be in the trailer with other things boxes and a bed

Been there, done that. Buy heat packs and pack them into insulated boxes (use blankets/quilts), stuff with styrofoam peanuts/newspaper, or whatever is needed to prevent shifting/crushing. Good luck....or move during temperate weather :)
Another option is the plants go in the cab with you where they won't freeze?

Tena, First question is: Do you have a heated location to pack and unpack? Packing especially takes time, and that means an open unheated trailer. You might get lucky in NM and land there on a mild day to unpack, but I doubt you will find any temps in Montana suitable to exposing your orchids to while you pack the trailer.

Some of the orchid packing is going to require you to work fast-having sawdust, or perhaps some kind of small Styrofoam pellets for insulation on hand is critical. Put a layer of the insulation in the bottom of the box, and place pots on this. You can stack small pots inside larger pots around the plants, then cover the pots with the insulation material. Sawdust, or pet bedding shavings is best for this because you can sprinkle water on this and the shavings will retain the water, increasing the thermal barrier in the box. Cover the pots with the insulation material this increases stability in the box and wetting the material increases its thermal protection. You can put long lasting heat packs in the box if you think it necessary. Put them in the center of the box on top of the insulation, away from direct contact with plants. Another possibility is putting a gallon jug of HOT water in the box with the plants. Getting jugs filled, packed in the boxes, boxes sealed and packd in the trailer and the whole thing closed up and on the road while the water is still hot is going to be a large engineering problem. (on my move we stopped in Oklahoma City for the night (small children made this a necessity) Temps were well below freezing and I was parked in an open parking lot. I filled a 5 gallon bucket with hot water and sealed it up in the trailer for the night. Had no cold damage to any plants). I would suggest getting at least two 5 gallon sealable containers, and filling these with hot water right at departure time-seal these in the trailer and GO!

You need to get the smallest covered trailer available that will comfortably hold your load. Make sure the doors close tight, and there are no holes in the trailer anywhere. I suggest you talk to the U-Haul people and tell them what you are doing, and see if they can recommend a way to get a 12 volt heater hooked up inside the trailer. Listen to everything they say, because if they can’t/won’t do the job, you may have to do it. An auto parts store might also be a suggestion.

You need to pack your orchids in thick walled cardboard moving boxes (U-Haul has these). Do not use cast offs from liquor stores or big box groceries, etc, etc. When your boxes are packed, you want to build a cube of plant filled boxes packed tightly together inside the U-Haul. Any boxes that won’t close over tall plants go on top, and tie the flaps of these boxes closed as much as you can, and perhaps throw a blanket over them. Use some kind of plywood or flooring on top of boxes to evenly support the weight of the boxes stacked on top of them

You say your trip will take 20 hours. If you can, plan to travel in sunny weather-Plan to leave in the early AM between any storms. Sunshine on the trailer roof will increase internal temps. Travel straight through, and if you have to stop for a short nap, do it on the destination end of the trip where the weather may be warmer. If you arrive and it is cold, after driving 20 hours you are not going to want to have to unpack a U-Haul and get orchids inside out of the cold.

Having a heated location at both ends where you can work and pack at your leisure is critical to a successful trip in your case. A friend with a heated garage, or something similar is something you will really need, to protect those plants.

Carefully map your route to make it the fastest route, but also be mindful of staying on major highways where you are more likely to be able to get help if needed.

After all this rambling if you have additional questions post on here, I’ll monitor this thread until you arrive. I am sincerely interested in hearing about your trip. Good luck, and God’s Speed.

Bill

Dbarron, I have 3 big German Shepherds that will be in my Jeep with me

I would buy foam ice chests and those big heat packs for hunting. Don't let the heat packs touch the plants.

ETA: I would think it would be okay to lay the plants on their side.

I order 72 hour heat packs: they guarantee at least 70F in book box size for 3 days. i transfer on auto train going for 17 hours (to 24 if late..) from DC (usually around 40f dropping to 32-34F in carolinas) to orlando.

boxes are packed in a car , but they usually open windows in the car (dont ask me why), so there is a considerable chilled air-flow.

i pack them into a car with heat packs on the night before, as we havecto drive 5 hours to get to DC. all my tropicals do well thru transition (including a dozen phals).

as a precaution you can line the boxes with large bubble plastic(bubbles to the wall , flat side to the plants). seal all seams with postal tape. for larger then book box volume (square moving box) use 2 heaters.

Oh, and make sure there is a good amount of paper towels near the plants to absorb condensation: they will sweat a lot!

the 72 hr heat packs can you get them on amazon, is there a particular brand to look for? thank you so much!

Yes, Uniheat 72 hour 10 pack. on amazon

https://tinyurl.com/yckh28xv

Yes! Thank you exactly what I ordered!

Then it is just the packing left..hope your overnight temps won’t drop too low!

i wish waiting on my house to sell