How much snow do you get where you live? If you do get times when the weather gets snowy/slippery/icy ...I hope that you're not going to be mounting summer tires on your 20s...because even though you may have an AWD vehicle...you still need tires that can handle the conditions you'll be driving in.
Remember, tires are like shoes for your vehicle...and the tires mounted should be designed for the conditions they'll be driving in. For instance, you wouldn't run track in slippers, or go rock climbing in flip/flops, or backwoods hiking in roller skates.
I only mention this in case you want to reconsider keeping your old wheels and mount dedicated winter tires on them for better winter driving...especially when the snow flys and the ice storms hit.