rethinking Micro Four Thirds in 2016

Alex Notpro wrote:

In particular, I'm wondering about A7II + A6300 or Canon 5DIII + M10 to replace E-M1 and E-PM2 respectively.

Thoughts?

Like you, I moved to m43 as the main system in 2012 with a couple of E-M5 bodies. I have added a couple E-M1 bodies as my main workhorses. I came from Canon with 1Dmk3, 5D2 and L glass, and for serious outdoor stuff in my late 50's at the time, it made sense to try something weather sealed but light.
I still work with lots of gear, including Sony and Canon with fellow pro's and I suppose I'd recommend considering the handling issues. For example, the m43 lenses are small and light such that it's easy for me to swap lenses in the field rather easily with a body in one hand and handling a swap in the other. With my Canon's and larger lenses it wasn't safe. 
The bulk of your gear will definitely increase if you move to a sensor system that requires the larger and heavier lenses. If that's not an issue, then no worries, but I'd think about that.

My personal feeling is that for general all weather, all kinds of photography, you'll miss the EVF in the Canon 5D3 and it's really a bit dated in terms of user functionality compared to the E-M1 and newer Sony cameras. If I had to go on assignment and couldn't take my m43 gear, I'd pick the Sony over the Canon if weight and bulk are important considerations. I've shot the a6000 and A7R and A7R2 and they're very capable. They're kind of popular with Canon shooters because Metabones makes it possible to use their Canon EF L glass on the Sony bodies with almost perfect results. So when they need the compactness and an EVF would be handy, they can have the best of both worlds.
When I'm going on a trip, heading to the mountains, or going on a day field trip I really appreciate the compactness and weight savings I have with two E-M1 bodies, and four lenses and an extender that get me from 15mm to 400mm rather easily. I'm rather intrigued with the new Panasonic 100-400, as well, as I sometimes miss the 75-300mm I took when I went to China and then sold when I got back. The new Canon 100-400 is an awesome lens, and the 70-300 is nice too, but they are much much larger, bulkier and heavier, not to mention the cost of pro level Canon lenses. So these are things I think about.
If weight and/or bulk is not really a factor for you, then this year is probably a good year to consider a different system, since both Sony and Fuji have really improved their lens selections. The Sony 70-200 f/4 is a very nice lens and works well on the a6000 series. The Zeiss 16-35 is also very sharp and has overall very nice image qualities that give it a special look. When I use the Sony bodies, however, I do miss some buttons and configuration access I have in the E-M1 or that Fuji places on the body in dials. But it's all what you get used to. I'm not missing any shots that another system would give me at this time, and I think I'd miss some due to weight and bulk issues were I to switch back to Canon or over to Sony at this time.