I was forced to buy a minivan this year because my kids are too big now for an SUV.

We bought the Honda. I've owned a '95 Voyager, '97 T&C, '03 Venture, and now the Honda. As long as you have traction control you should be OK. The van is heavy enough, that most of the time you're fine. I'm half way between Chicago and Milwaukee and saw more than our share of snow in the last few years.
I looked at the Toyota AWD but the reviews said it had many issues. My mom has a FWD Toyota Sienna, and I can't stand it. I've driven it a few times, and it's very loose feeling to me. Not to mention I swear it's at the dealers at least once every six months and trust me, a 68 yr old woman isn't nearly as hard on a van as I would be. The sliding door on the passenger's side has been replaced twice, and not due to any accident. It just stops working and fitting correctly. Very odd.
My biggest deciding factor on the Honda was it's size. It had more interior room than any of the others. I was getting rid of an Acura MDX and was impressed with it's reliability, so that was a factor as well. Only car I've ever owned that never needed service except for oil changes, tire rotations, and blades, and we've owned at least one vehicle from every manufacturer, both foreign and domestic.
Good luck with your decision.