Someone correct me if I'm wrong, but isn't that the idea behind continuum in Windows 10?
This is exactly why x86-emulation-on-ARM (http://arstechnica.com/information-technology/2016/11/x86-em...) is a very exciting project from Microsoft.
As mobile chips continue to improve, emulating x86 becomes a viable way of tapping into the huge Windows ecosystem of applications when not running on battery power.
I think this is Microsoft's last shot of becoming relevant in the mobile space.
You could combine it with something like a nexdock to also turn it into a laptop. Would be cheaper than getting a phone, and a desktop pc and a laptop, and it would avoid all those nasty issues with keeping devices in sync.
The qualcomm 820 already performed at core m levels, and the 835 is 25% faster, so it should be fine if paired with enough ram and storage.
The problem isn't power. Phones have been powerful enough for about 5 years (since around iPhone 4s, as a means of dating it).