Brass Band in Hackney ! Help !

Hello !As some know already, my French brass band is coming to town from 25th to 27th May. We will play around Hackney for the whole weekend (planning to do a BBQ in Victoria Park depending from the weather). Only problem, I am still struggling to host 6 of my guests. I am already hosting 10 people at mine. I am just looking to a empty space or even a garden where they could sleep on mattress/sleeping bag. If anyone got a tip or advice (I tried community halls but they close early).Thanks