I have two 6' oleander trees that are just great. Trying to figure out my options for overwintering. Would love to hear from anyone in zones 3-4 what they've done. I know they are poisonous and I do have cats, so in the main house is out of the question. With that in mind, what do you think of these options?

1. Unheated attached garage, off the floor. I read somewhere that a guy in Ontario said he put the pots inside of a large cardboard box and then insulated with crumpled newspaper between the pot and box walls. I assume he left the canopy part open, but I don't know. I think parts of Ontario are warmer than Minnesota/Wisconsin...and also, I've read that Oleander can't take below 40 degrees, so not sure about this for me.

2. NW corner of my basement, there's a room I could keep closed so no access for cats, but there's no window in that room. The room is about 12 feet from the furnace, so I imagine that the winter temp there could be in the 50-60 range. ( We rarely even put our heat higher than 65 in the winter. ) In this option, I could either go with all dark, or set up a timed light.

I'm concerned about bugs with both options, but maybe could keep them sprayed???

Would love to hear from someone who has tried this, thank you!!!