20 inch square setup for winter/snow tires?

[1norseman]

Originally Posted by CatalinP

I read your post above, but, fitting the same tyre size on a 10" and on a 10.5" J rim does not seem so great idea... The tyre on the 10.5"J rim will stretch more, the overall diameter of the wheel will be less, therefore giving potential problems for the transfer box.

That is incorrect:
Actual diameter won't change because of stretching a tire on a wider rim, the belts in the tire won't allow it. However stretching a tire, will affect the contact patch/width somewhat.