Depending on the SUV, the minivans may have comparable ground clearance. If the SUV you currently have has AWD and not 4WD, there's a chance the Siennas AWD system is better as well. Plenty of people drive FWD or RWD sedans and hatchbacks during mud season. I wouldn't worry about it too much. I'd recommend test driving all the vehicles you are considering and looking into the ground clearance as well (Sienna 6.3", Pacifica AWD 5.4"). I'd also recommend the Sienna over the Pacifica for reliability reasons.