You may have to protect them. Anything below 0F may be iffy in a pot. Other then that shoot for as big of a pot as you can get. I fruited nectarines and sweet cherries in 1/2 whiskey barrels this year. Seem to work fine. Just make sure they get enough water and nutrients. I used a lot of wood in my soil mix, along with perlite, compost, etc. I'm not too worried. Just make sure it can drain. Make sure you feed the tree with a fertilizer with micronutrients.

If i was to pick, i'd go with a heavy duty plastic container. Wood is very heavy and annoying. Have a dolly or some wheels on a board to move them around.

franktank,

How do you protect your pots in the winter?

Thanks

They go right in the garage :) I have a large attached garage and only one car, so we have a lot of free space. They do outstanding in there. I've stored quite a variety of fruits/berries in there over the years. I live in a VERY cold area with normal mins usually approaching -25F, so the garage easily drops to 0F or lower.