A4 owners UNITE!
honestly, its different and the clearance plays a very little part... Quattro Haldex (TT, A3, etc.) vs. Quattro Torsen (A4, A6, etc.) what you need to look at is how each system works, and in simple terms, Haldex is electronically controlled in which its higly biased in the front drive wheels until the haldex unit senses that the rear wheels are slipping, thus sends more power to the rear drive wheels. Torsen is all time all wheel drive, in which the split, depending on the car and in most cases is, 60-40 Front to Rear (correct me if im wrong)
getting away from all the technical and theoretical stuff, ive driven both a b8 a4 & my tt in the snow (same amount of precip), and ill tell you that the a4 handles itself significantly better than the TT. the a4 crawls up hills where the tt finds itself struggling to get up it (both cars had plenty of clearance)
but seeming that youre in Reno and snow isnt as significant as it is in NYC during the winter, the TT should get you around to where you need to go