Need bnb / guest house / farmhouse for 50ppl in Islamabad.

I'm hosting up to 50 people (extended family) for one night this coming December and need a place for everyone to stay.

Ideally I'd like a single venue so it's easy to manage. Hotels get really expensive at that scale, so I'm open to any and all ideas.

My fallback is an army mess, but past experiences there haven't been great.

Any suggestions pleaseeeee