We have a rib 112 and full width kitchen cupboards and when we went away last summer for our first long trip with 4 of us (2 teenagers in the back), we had a massive awning (4 berth inner tents) plus 2x 2 man tents and sun awning plus a hold-all of clothes each (I bought 4 that fitted perfectly across the back side by side), 2x toilet tents (1 for toilet, 1 for shower), porta potti. Everything packed in the “boot”, we also had 4 full size bikes on the back and I think for a T28 we were pushing the limits! Because of the bikes we made sure that anything we needed during the day was in the van, so shopping or beach stuff etc and so accessible.
Basically, you should be able to fit everything in the back. You then have the space in the living area for shopping, beer or whatever you pick up or need along the way.