Yeah I keep looking at the 7 series as well, some of the older ones. I want the Mini for country lane lunacy and something luxurious for the motorway trips. I don't do a huge mileage on motorways so not too concerned about the poorer fuel economy - it would be more getting around town that's a concern. The only major problem with getting a 7 series of the XJ is that I often give the fiancee a lift to work and we need to get a bike in the back! The XJ boots are massive though so might fit. If not, would need to keep the Focus and the Jag which would be less than ideal!
The other option is something like a X Type estate. A nice compromise between both.