Hi,

I don't know much about the Ulysses and how the seating works but if you need to convert it back to a 7 seater on a regular basis I guess you would be looking at some kind of removable conversion.....

What I'm thinking is set the back up in a way that is easy but gives you more room to play with i.e. if the back seats can be easily removed or perhaps laid flat?   Using that as your basic space (and the maximum amount of hassle you want every week), I would probably build some kind of units and maybe a bed frame that could be put into the back, potentially over flattened down seats to give you a bed base and some surface space.  The idea being you could remove this again at the end of your trip away. 

You could then put in some bedding, carry some limited kit (cutlery, plates, clothes, food etc - cheap plastic crates make ideal movable storage for these things) and perhaps get a cigarette lighter travel kettle etc.  If you can work in some good sleeping space it totally opens up where you can go (and it beats camping!).  One issue would be things moving about, so you may need to put in some kind of permanent blocks to fix or slot things into.  

For cooking you can always carry a camping stove.  I know folk who've operated these in the back of vans but I wouldn't recommend that in car!!  Insulation mats with suckers would be ideal for blacking out the windows for privacy (there is an article on making them - window mats).  They're removable, easy to store and mean you don't need to faff about with curtains.   

Ultimately if you need it to work as an MPV during the week it's going to limit what you can do but I reckon their are some options in there.  Have fun.......