Here only one recommandation. You take it or not doesn't matter.
Run your Paintball field, during winter find your weak day or evening and make a special for the Airsoft community.
In montreal some players play in a paintball field during winter.
They have the wednesday night per 2 week. it's 25$ from 18:00 to 23:00.
It's still expensive if you compare to outdoor private games, but it still worth it. They have actually around 20 players every 2 week all winter long.
Just my input.