Unless you have a ton of horses and you're in a big hurry to get over the mountain pass (in which case you should leave earlier).  Outbacks are way better in the snow than any SUV I've ever driven (I drive up a mountain in N. Idaho every day in a Subaru).  You can easily run shuttle for 6 (72" crossbars will allow 7 actually, I've done it).  I assume the boat you speak of is a small duck hunting boat, which an Outback could certainly handle (tell me it's not a cabin cruiser).  Time to sell the SUV I guess.  You won't miss it.