Looking for an overnight retreat location for a Stanford student org

We're a Stanford student organization looking to host an overnight leadership retreat for 16-20 people. The dates will be one night on 10/21-22, or potentially two nights on 10/20-22.
This is not a party and there will be no drugs/alcohol.
Our budget is about $500-600, but we are flexible.
Our organization hosts a retreat every year but airbnb prices are not sustainable for us. We keep clean and have received 5 star reviews for the last two airbnb stays our group did last year.

Please contact for details if you think you have a suitable property or lead. We appreciate any help!