Oh shit oh shit oh shit oh shit dude, you are lucky. I studied abroad there 2 years ago for a year and the skiing was amazing. Portillo will blow your mind, I'm not kidding. They only allow 450 skiers a week, so there is NEVER lines or crowds, there are only 2 hotels, one for rich people and one hostel, meals are all you can eat and all inclusive and so good, the resort sits right on a beautiful mountain lake that is crystal blue, and all the ski runs run right down to the resort. When I was there it snowed like 3 feet one day, there was fresh pow and fresh tracks all week. I didn't bring skis because you can rent almost any model from their proshop for cheap as hell. Find ANYONE on twins and ask them if they want to build a gap over Tio Bob's, the on hill bar. Most likely they will say yes and you will have the best session of your life, throwing down while looking out over the Andes and a mountain lake.
If you get time go to Valle Nevado and El Colorado, both so dope. El Colorado has a sick park and Vallen Nevado has the best super pipe in South America.
Seriously those Chileans are serious about skiing,