Where to visit Northern Italy - Dolomites in Winter-Skiing

We really enjoyed staying in La Villa, Garni Tamarindo. We were there in September. Lovely guesthouse, great breakfast. The owner's brother owns a nearby place Montanara, I believe. Very nice and reasonable. 140 Euros for 2 nights.

Cancel Cortina and go to Selva di Gardena (Val Gardena), or the previously posted Alta Badia. Skiing is much better than Cortina, just as pretty (prettier, I think). It is also easier to get to from Milan. Driving to Selva is all in valley with good roads.

Be sure to do the Sella Ronda, a complete circular day ski tour around the Sella Massif. You can do it clockwise, or counter-clockwise. All lift connected and mostly easier runs. Direct access to the route either from Selva or La Villa.

Another don't-miss ski half day tour is the Lagazuoi Valley, which is easiest to get to from La Villa. Ski to Armentarola and take a bus or taxi to the top of the pass. There will be a big line in the parking lot, just get in line and a continuous line of cabs and buses will pick people up for the ride up to the top of the pass. Should be 5 euro per/p or there about. At the top of the pass ride the cable car to the top and follow the red run down the isolated valley back toward Armentarola. There are a couple of rustic restaurants along the way. When you get to the flat, a horse-drawn sleigh with 2 or 3 long knotted ropes awaits, pay the man 1 EUR and when the ropes are full (50 or 60 people), the horses will pull you to Armenterola. You can also reach this from Cortina as the local ski bus goes there. Cortina is on the other side of the pass, but you would need the taxi/bus queue to get you back to Cortina.
https://www.youtube.com/watch?v=nUWo57lkrD4

"This will be the second time we will be traveling through Milan without seeing the city are we missing out? "

That depends on you and your interests. If you like big busy cities, or if you want to see a part of Italy that doesn't fit the some of the stereotypes, you'll like it. There's lots of art treasures (not just the Last Supper, but also the Brera Gallery, for starters), some good food (and all kinds of foreign food you can't get elsewhere in Italy), and a faster pace and more cosmopolitan ambiance than in other Italian cities.

On the other hand, if you don't want a big city atmosphere, or if you'll be upset at a place where "the sweetness of doing nothing" is not nearly as important as the rest of the country, you may hate it. It's as far from a Cinque Terre or Amalfi Coast vibe as you can get.

I happen to like it a lot, but I certainly understand it's not what many people are looking for on their Italy trip.

Thank you everyone for your responses, I appreciate it. Very interesting to see everyones perspective.