There's a kosher 13 bedroom house in Monsey that's rentable for weekends etc
http://koshermansions.com/united-states-of-america/new-york/monsey/monsey-forshay-mansion-with-indooroutdoor-pool
It's on Jay Court in Monsey.
Minimum 2 nights stay and it costs $3,700.
At 13 bedrooms fitting 30 people I assume there's 4 bedrooms with 3 beds and 9 bedrooms with 2. Either way the max would be 13 couples and that's if (big if) they can fit all their kids in their bedroom on blow ups/pak and plays.
That's $284 per couple. Kosher and eating would probably be much simpler than a hotel but on the flip side, people would need to bring blow ups/pak and plays. Would probably be better for warmer weather when the outdoors can also be utilized.
There's 14 bathrooms but since this was originally built as a residential home, there probably aren't bathrooms in every single room. While that sounds crazy compared to a hotel, when being a guest at someone's house you would be okay with sharing a bathroom so it's not soo crazy with people that you are hanging out with as friends anyway.