I skied with a brace about ten days after my MCL tear (it was probably against medical advice, but I had a preplanned trip with my brother we'd spent months coordinating. I'd like to say I was young and foolish, but actually I was just foolish.) I found that I had much less trouble skiing than I did walking.
Several suggestions/free advice worth what you pay for it:
1) lots of ibuprofen reduces swelling. And lots of ice in that first 48 hours.
2) go get physical therapy. They get you set up with range of motion exercises, stretching, leg strengthening exercises. And the well equipped ones can use ultrasound (or some darned thing) to stimulate healing.
3) if you know a REALLY good massage person, as you're healing (beyond the initial 96 hours), have them massage the area. I'm told that stimulates blood flow to the area (which will also feel slightly warm to the touch) to stimulate healing.
4) as you heal, pay attention to how you walk. Months after my MCL injury, I finally realized that I had adopted a new walking gate with (hurt leg) toe out (opposite of pigeon toed) while the other toe, as before, went straight. The resulting funky walk made my LCL hurt. I fixed the walking gait and my other pains went away.
5) I wore an elastic knee brace skiing for a while on the hurt knee. I'm not sure it did anything other that make me be constantly aware of the hurt knee and its position and how it was bending in what direction, but that itself was a good thing.
6) If they have you doing stretching exercises for the hurt leg, unless you're very flexible to begin with, do the same stretching exercises for the good leg, or you'll end up with a major flexibility imbalance. (Something like 6 years later I can still stretch one calf more than the other--because I stretched that calf as part of my rehab routine.)
7) After you're all better, consider doing balance exercises. Some report damaged priopreception from having a torn MCL, and they have to work at getting back to where they were.
Good luck, and recover fast. The nice thing about MCLs is that they can grow back, even on a grown up.