Cheapish to stay/in near London for a family of 6

[notso]

We have Merlin passes this year and want to make the most of them so are looking to stay in or near London.
I am struggling to find anywhere to stay that sleeps us all and doesn't cost hundreds of pounds a night.
DC will be 14, 9, 3 and 2.

TIA

Camp, yes there are campsites in the London area. University accommodation. Travelodge. Youth hostel. Any preference where you want to be? Or house swap?

Check our air bnb or short term lets.

Check OUT, not check our.

www.leevalleyboats.co.uk/chalets_availability.html
housing.london.ac.uk/cms/university-housing/visitor-accommodation/

Thanks all, will have a look at all suggestions.