Yeah, I saw some random icy patches this morning, too. I'm just going to choose to ignore them (or actually just ride carefully).
In my head the problem with swapping them is mostly the full chain case. But I also have a dyno hub, internal gear hub, and full fenders and I've never actually tried to swap the tires on this bike - I take it to the bike shop. I know I'm paying $10 for something I could clearly do myself but for some reason I just can't bring myself to try.