What kind of excuse do you give to leave home for a few hours on a snow day for some hobby entertainment?

specially since no-one is in the office and you can finally have some peace

Always good for a couple of hours.

So maybe you are out to find a lake river hell a puddle to practice your skating hahaha

Say you're going to two places.  For example, I'm going to the office then stopping off at Home Depot (Lowe's, dry cleaners, auto parts store, library, etc) so that if a check of the office is made you could easily be somewhere else.  Easy to explain you were on the move.