10-11-2021 11:44 AM
My first thoughts is the 70D as a platform would not be my first choice for long video work. Certainly draining two batteries I would consider a long time. The 70D is just about in the transition time area. It shoots video but it really isn't a video camera.
I know the latest crop of cameras seem to have no or at least few issues shooting video. I imagine Canon realized the need and designed them differently. I hate to say better but that's really what they did. If your goal is mostly video you might want to upgrade now anyway. I am not sure even the 90D would be a whole lot better (doing mostly video) but it probably is better.
One of the new mirrorless cameras would be my choice. The 90D is a grandtastic stills DSLR. It is the best crop style DSLR made, IMHO. I have always though, after spending a day with one, I would buy a 90D with the again grandtastic Sigma 18-35mm f/1.8 DC HSM Art Lens. Say what you want about FF but that combo is as good as it gets.