DTD should have sale come Black Friday. Save your pennies and buy a set then, perhaps. Cruise your local CL and see if anyone decides to sell some Caravan takeoffs--actually, look and see what else will bolt up properly, same bolt pattern, offset, etc.
Heck sometimes you can get good takeoffs (steel rims with good condition rubber) on CL.
While I agree that a good snow tire is always better, there is something to be said for getting decent all seasons. That way you don't have to put snows on at Thanksgiving "just in case" or having to sweat out every predicted flurry. I have the RT43's and will recommend them as a decent tire. Good in snow (for an a/s) when new. I suspect a heavy Caravan might chew them up relatively quickly, not an LRR tire (or weren't when I was shopping) but a decent tire.