It is a lot of work, especially if high school was easy for you. I typically never had to study or try much and still did very well in high school. As a result, college was a rude awakening for me. I'm majoring in mechanical engineering, and while I find it interesting and I love it, there are times when it just sucks.
Freshmen year isn't too bad, you will have more work than most of your friends though, but a lot of the classes are taken by all tech/science majors. At my school it is 16 credit hours freshmen year, and 20 from then on out. I would still go out a bit, but being a freshmen guy and not having that many options for actually helps.
Sophomore year it is more work, for me it was still mostly introductory type classes (statics, dynamics, strengths of materials etc.). I actually had a harder time with these because it is just a lot of what seems like busy work to get you to learn the skills. In a way, the upper level classes with higher workloads were a little easier for me. I went abroad in the spring (my school has this available for engineers, I loved it). Traveled all the time, went out usually 4-5+ nights a week.
Junior year is when it gets pretty rough. You need to have good study skills, motivation, all that to make it, and you won't sleep much. For most of the fall semester I didn't go out on weeknights. It was really hard for me to keep up (rehabbing a shoulder injury and a few other commitments), and I ended up dropping a class and switching to a 5 year plan (I am a double major with International studies as well, requires 16 credit hours on top of engineering, or 40 more than most other majors). Now, my junior spring, things are going better. I am back to taking 16 credits, I have much more time to have a balance with my work and school. I still spend a lot of time studying, and I don't go out quite as much as my friends, usually 3 nights a week now, sometimes a little more depending on the week. I am also just happier, I have time for things like watching netflix, hanging out with friends, taking an occasional nap, going to the gym (3-5 days a week depending on work).
As far as skiing goes, I am in PA, so I go for a few weekends with the ski team, but that's pretty much it. If the snow was better and I had my car (I usually get it for part of the semester), I would be able to go more. Before going to college I talked with my parents and basically realized that I could have 4 (now 5) years of good skiing and then do whatever, or I could put that to the side during college and make enough to be able to afford to ski more when I'm out of college. Also, I get 5 weeks (sometimes a few days extra) for winter break, and I will sometimes ski for spring break. My freshmen year I got 30-35 days at my home mountain, and about 12 more while at school. After that I was abroad/injured, but you can still get a decent amount in, and more if you have a car/ride and a good schedule.
That's how it has been for me, feel free to pm with questions. Not quite a typical experience, but maybe it will help.