I’ve had a lot of luck here in central Alberta with “tree tubes”. I’d attach a photo, but I’m not sure if we can on this forum. Basically these tubes are 4′ tall and about 4″ to 6″ in diameter, and are usually brown. I cut them in half to get a 2′ tree tube. Just do a google search on “tree tubes” and you will find sources.
By putting the tree tube right over a new graft on a rootstock, the graft is protected from the wind and the tube acts as a mini-greenhouse. The grafts are more likely to be successful and the graft, once it takes, grows much better in the tube than it does outside the tube from what I have seen. You simply tie the tube to a stake and it can take any amount of wind.
You absolutely MUST take the tube off after a good frost. You can put it back on if needed the following spring. If you leave the tube on over the small tree all winter, it will certainly die. The tube acts as a greenhouse, and in March or early April the heat in the tube causes the tree to come out of dormancy way too early, and it dies. Don’t ask me how I found this out. But tree tubes are awesome for new small trees in cold climates like Alberta and Alaska.
And Re the tubes, I tried them after reading your website and they are indeed worth their weight in gold.
FWIW, for anyone wanting to try these, large plastic soda pop bottles can be used to similar effect. I cut the bottoms off with scissors and leave the tops open without a cap–they work fine on shorter plants. It is also possible to cut off the tops (necks) of the bottles and tape several together to make longer tubes, but the real tubes (I purchased mine from a vineyard supply) are easier to assemble if you have a lot of grafts.