I think your observations are spot-on.

I know there's lots of bent riders that ride them all winter, but... I've found that riding in slippery stuff requires a lot of body english, so just like when riding technical MTB stuff, an upright tends to be better in snow and ice. It's not as comfortable, but I don't put in so many miles in the winter anyway. Besides, why put your nice bike out in that nasty stuff? DFs are a dime a dozen. Let them get rusty.