Many schools have days where they go to a gym or facility and get some work in. Ask your coach if your school does that. Many times it isn't the coach (not sure if coaches are allow to do off season off campus activities) but many times dads or the booster club will get the funds to get a facility.

outdoor winter scrimmages are hit or miss, icey hard ground, bulky layers and broken sticks. For that play hockey, lol.