Overnight products for hair?

Winter is coming and between the dry air, the constant beanies and the fact that my hair is curly, I always end up chopping my hair after winter because it's just so damaged no matter what I do.

This year I have invested in a satin cap which I will wear under my beanies, but are there any overnight conditioning treatments I can leave in my hair (nothing oily if possible)?

I'd like to save my hair this winter.