Get a big cheap styrofoam cooler and put your bareroot plants in it. When you stop for the night, bring it into your motel room and air the plants out. They should be all right waiting in the car when you make various types of pit stops along the road there. I usually put a heavy book on the lid to prevent any air seepage or tape it down. When the move is over, you have a cooler to use.

Don't worry about them being out of s/h for even several days.

prewarm the car and just use a plain old cardboard box. I've done it several times when I do some winter purchases when out of my home state. the amount of cold they get exposed to when you walk out to the car is minimal. I've transported them in bud without losing anything

watson's way may give you more piece of mind, but most of the styrofoam coolers are too small

Thanks for the advice. I may use a box just because I have so many and many of them are large. I have cymbidiums, too. Would you wrap each in something like bubble wrap or just line the box?

I'd just insulate the box. I wouldn't bother with each plant, other than making sure the label is firmly attached to each one. Just get a cheap punch and punch a hole in each label and attach it to the plant via wire to even string.

What a great excuse to take a good look at all those roots! You may even discover some things you needed to know...bon voyage!

60 orchids in the car... I don't think so, you will never have the room. You're right not to trust them to a removals company though, so my solution would be... leave then to a trusted friend, preferably someone who has a few tender plants, until spring comes round, then you'll have an excuse to go back and tell them all your moving stories...