The work will most likely not be too much, unless you are extraordinarily devoted to your Uni work. When I lived in Sheffield, I was skiing 1-2 times a week, dryslope or indoor. However the dryslope in Sheffield is now closed.
If you're really in to skiing, I would probably consider studying in Austria or France instead. Don't know much about France, but Austria has Innsbruck and Salzburg, two Uni cities pretty much right in the middle of the mountains. I would recommend Innsbruck, you can get out of class, and then be shredding 30 min later.
Feel free to ask any questions regarding Innsbruck or Sheffield, I have pretty extensive knowledge on both of them.