My dad has X Trail (out of Motability scheme) and from what you have described, it will be challenging for you, especially on long trips. Although the car is very nice, it isn’t comfortable enough to accommodate 7 people on mid to long range trips. Have you tried to rent it for a day or so via Enterprise rent-a-car or the likes of? On Motability I had for almost five years VW Touran SE Family package. Yes it is ugly to say at least, but was very comfortable for all 7. The pain that I saw they about to increase the price, but if you are lucky than hopefully you will find some cancellation by Monday.
Wouldn’t need the 7 seat version, just the 5. Only 5 of us in total including driver