Hey, Jeff. Let me start off by saying that I aspire to achieve your level of photography. As many have said, it's outstanding. I have some experience, though, that I would like to share. Feel free to ignore it.
In my career, I was a mechanical engineer and a software engineer. Anyone who knows engineers would be the first to tell you that we are obsessed with details. When I retired 7 years ago, my kids encouraged me to buy a DSLR. I did, and I've been on a journey ever since.
I started with a 60D and the EF 70-300. It wasn't good enough. I added the 100-400 v1. It still wasn't good enough. I've gone through the 70D, 7D, 7D2, 5D3, and 300 2.8 II since then. Nothing was good enough. When I got the 100-400 II, I got closer. Two years ago, I finally sprung for the 1DX2 (sold the 300 2.8 II to get it). That body is incredible. It *loves* to take pictures. It does whatever I ask it to do, and it does an amazing job with incredible ease. I've since added the 5D4, and it's not a 1DX2.
I've not tried any of the Sony equipment. Perhaps it would take me somewhere that I haven't been. Without that, though, it's hard to imagine giving up the 1DX2 for anything. I would give the 1DX2 a go before switching to anything or hoping for a 7D3. Your comment of "I need the crop sensor" was me before the 1DX2. A crop from the 1DX2 far exceeds anything I got from a native 7D2 image.
Your dilemma is real. I hope you figure it out successfully and continue to post here for years to come.
I absolutely agree! The 1DX2 exceeded my expectations! It is in another league.