I use an event shelter / tent very similar to the Coleman event shelter,
It came from millets , from memory it was about £120 , included 4 detachable sides, so its a lot cheaper than the Coleman when you consider the Coleman does not come with sides. ( zip off) no windows but mesh panels high up to allow light and air in.
It’s easy to put up, takes up a relatively small space in the van and adds 16m2 of living and storage space when onsite and can
Great for a chill out area and extra storage,
I’ve slep 6 : 4 in the Cali, two in a drive away awning and the part tent for communal living, storage etc.
Not all sites will allow a tent that is detached from the van, check it out carefully, licensing authorities sometimes stipulate the tent has to be attached to the van ( I.e awning)
We used ours in France last year, wind out awning used to bridge the gap between van and tent, simple traps used as side panels for the wind out, works fantastic and is slightly easier than a drive away, (both have advantages and disadvantages
Try looking on the multicoloured auction site for second hand drive away awnings also.
As is always the way there is no perfect set up, but the party tent adds a serious amount of extra “ living” accommodation if sites allow them.
I think this is it
Good luck