Sounds like you need to test a Fuji X-t2. The fuji lens lineup is extremely impressive!!
You can buy a battery grip that would increase shots to 11 fps and longer 4k video footage.The sharpness in the video is excellent with little jello rolling shutter. Shoots 6k so that you get true 4k uncropped similar to the panasonic gh5. Shoot with Fuji's film simulation during the video and it's almost like a graded video straight out of camera. Haven't heard much people complaining about the X-t2 overheating in 4k vid mode.
I've recently seen some example video of the gh5 being impressed. I thought they were low light but actually they were shot at unchallenging iso 1600 (must look for those videos). $2700CDN bucks for an M43 sensor is alot of money considering how it'll have the typical difficulty in high iso shooting in low light.
I still love shooting with the 80D. The stills image quality still is one of the best Canon crop sensors I've ever used. IQ surpasses the 1dmk3 by a huge margin!!! Video with adobe premiere treatment is quite nice.
Drisley if you look at the X-T2 it's often compared side by side the Nikon D500. The D500 destroys Canon's 7dmk2 virtually in every categories of a sports camera in the crop sensor world.
My Fuji X-T2 high iso is a pleasure to shoot. The noise is not like the artifacting noise you get from Canon. Noise is actually pleasant looking. Colour does not look nasty like Canon when pushing it at very high ISO's. I want the 5d4 but so far for stills my 5d3 will do just fine for my events photography.
Go out and rent an X-T2. After analyzing my fuji files both 16mp and 24mp the image quality doesn't leave you with the feeling that FF is superior like back in the day when crop sensors were mediocre. I'm finding the image quality to be so close to full frame that I can probably go full on Fuji gear "IF" they had a better flash system. At least now they have a good EF-X500 ttl/hss flash on the market...finally!!!
So far I have zero regrets for purchasing my X-t2 and I still love my 80D. With the X-t2 I can comfortably leave my house knowing I can produce high quality stills with a prime lens with no hesitation. I can never say the same when I owned M43 smaller sensor gear since RAW files fall apart as you hit iso 3200. Stills I can comfortably shoot with the 5d2/5d3 with remote flash for receptions/events.
The new Fuji X-T20 is hitting stores this week. It's a mini X-t2 with virtually "almost" identical specs. I'll be picking up one of those too as it will also shoot amazing 4k/1080 vid with fuji presets.
Oddly I still cant let go of my Canon dslr gear. Fuji has smaller native lenses that are pro quality. I think I can still transition to Sony using a metabone adapter putting full size dslr lenses as well as using massive Sony native G master lenses on a tiny body. However I'll admit I like the fuji look more than the punchy contrast/vibrant Sony "look".
You gotta find what suits your needs and what feels good in your hands.