Personally, my ideal setup would be either the 5DIII or 6D and a really nice small portable camera. The type of small camera you get depends a lot on what you want to be shooting with it when you don't have your FF camera around. It also depends on what lenses you already have for your FF setup.
There are some really sweet smaller cameras out there at the moment from Fuji, Panasonic, Olympus, and of course Canon.
Just as an example, it might not have the greatest IQ or AF in the world but the Pana FZ200 has a 25-600 f/2.8 constant-aperture zoom on it. I don't have a lot of need for long telephotos but owning an S5 IS has completely put me off the desire to buy SLR lenses longer than about 200mm. It's easy to bring in to a stadium/arena concert in a small bag and shoot decent video from really far away. If you need better IQ, Panasonic also makes a load of stabilized μ4/3 supertelephotos that fit in a handbag. A GX1 with one of those would be a sweet compact stadium setup.
BTW you didn't really mention what lenses you have (other than the 85mm f/1.
or whether you have any EF-S lenses like the 17-55 f/2.8 that would influence your decision to keep the 7D...
I agree that if you do primarily sports & action keeping the 7D is probably a good bet, a compact camera won't hold a candle to it in terms of IQ and AF.