Some years back, I was using a 7D and bought a 5DII. I found the IQ to be much better, although the AF was not as effective. I continued using the 7D for birds, but switched to the 5DII for everything else. Agree with the above that the 6D should also be considered.
I suspect your biggest future issue will be lenses, as your standard zoom, your ultrawide zoom and your macro lens are all EF-S. Macro is a toss up for FF vs. APS-C, so I'd say that's not a priority. Also, most FF standard zooms start at 24mm, so if you use your ultrawide mainly at 15mm or narrower, you'd be covered for FF. I'd look into a used/white box 24-105 f/4L as a standard zoom to replace the 17-55/2.8 (the FFeq of the EF-S is 27-88mm f/4.5, so the 24-105 is wider, longer, and faster).
Good luck!