Juice them and freeze for later.

Christmas gifts to your family? Roadside fruit stand? ;)

I feel your pain. I have a use case for like maybe 2 lemons a year. But I can eat tangerines every day for the 4 months of citrus season.

Juice them and make some ice cubes to add to your water or to put in the blender added to smoothies or for use in recipes etc.

I am envious! My Ponkan tangerine is succumbing to greening and won't be around much longer, and I've already lost an old meyer lemon and a very young blood orange and Rio Red grapefruit = (

FWIW, I used to freeze whole lemons & limes and use them for the juice. Anything raw, though has a shorter freezer life than blanched or cooked things.

Marmalade?

Lemonade uses up a lot of lemons.

Is there a local church or community group that feeds homeless &/or low income people? Our church offers a weekly free luncheon to homeless folks, and is always looking for donations.