What's the best way to invest my empty basement

[Jeff Si]

I have a house in Kirkland, WA, and currently living there with my girlfriend. 

This is a 3 bedroom 2.5 bath SF house with a walk-out basement. My girlfriend and I are using the master bedroom and also the two other bedrooms as office since we are both working from home. The basement is empty. It's a pretty big, above ground, and has a door to the outside. Basically it can be treated an additional bedroom.

We are considering rending the basement out to make some cash flow, but so far we don't know what's the best way to invest it out. Here some the thoughts:

1. The ski season is coming. Seattle has one of the best snow in US so I'm thinking renting the basement out during the ski season. The caveat is Kirkland is relatively far from the ski resorts. Normally it takes about 1 hour drive to reach the nearest ski resort.

2. We are also thinking out listing the basement on Airbnb. But we never did airbnb before so not sure how much that would impact our life. We are very enjoying ourselves living in this cozy house. Sharing the house with a stranger is something we are hesitating about. 

would love to hear suggestions from you all about how to make the best use of the basement or even the guest bedrooms (My girlfriend and I can go to office even though we are not a big fan) to make some money. 

Thank you all!