Negotiating territory in a foreign bed

I used to love soft beds, and the double bed I bought while I still remained at home is one of these, upon which I've been sleeping for the past week or so. However, now, I prefer a mattress with a bit more support so it's taken me this long just to find sleeping positions that I can cope with and don't leave my back sore. Then Adam arrived yesterday and mucked up my whole system. He doesn't like my bed for the same reason he doesn't like 90% of all others - it's too small. He's always had problems folding his 6ft 5 inch frame into shapes that are amenable for sleeping. So, last night, as we hop into bed, there are butt scuttlings - of each other- back onto our respective sides of the bed. Both of us complaining at the same time that the space we have been handed is just NOT ENOUGH! Plus, you've got a soft mattress that rocks almost like a waterbed and I'm struggling just to locate some ballast. And then we've got the sheet/blanket factor. I have to be covered by something when I sleep; Adam is happy to go without. Then when I pull up a sheet/blanket, which may happen to brush over his calves or ankles, I get in trouble: "Stop covering me up!!" Ah, fun, fun fun. But we'll get there. We've had almost ten years practice. Or, one of us can go sleep in the spare bed in Riley's room, but neither of us want that! So the turf wars may go on....