I am in the south of England but the problem is the same. If you can put them in a shed or similar it will help, but it does depend on species. Most of mine have to stay where they are, I put my small ones shohins and mame in the shed also my Trident Maple and Quince that is in flower. the rest are where they have been all the time. Yes may get some damage but it will not kill the tree. If your trees do get covered in snow that will insulate so not a bad thing. We had frost in May last year that did more damage than all winter.
The other thing you could do is cover with fleece, I take the trees out of the shed each morning as it is getting warm during the day,
I hope this helps you,