@luliski be careful about running and skiing the same day, especially if you start skiing harder.
I've found injuries are my most significant running limiter, and skiing and running don't mix well. During ski season I'll take at least a day off between running and skiing, preferably two.
My running goals through ski season are just to run a couple of days per week and remain uninjured. I usually won't do any speed work unless there is a dry spell when I don't ski. I can get my speed back within 4-6 weeks that way, as opposed to taking all summer if I'm injured.
For me, swimming is the only thing that feels good the same day as skiing. It's great to get in the water and get the blood flowing, preferably with a workout where I'm not concerned about my times or yardage, i.e., not masters. Swimming at altitude is also a huge adjustment that requires a significant reset of expectations. It's really good for your swimming and overall aerobic capacity after returning home, though.