To be honest, as a Surface Pro 2 User, even with 8GB Ram in Phones becoming theoretically possible, i don't think i'd actually want to compromise any further down for my development environment ressourcewise.
I'm in the same boat. I picked up a bottom-model Surface Pro 3 during a startup liquidation and I'm pretty happy with it for VS2015, but I definitely agree that there's not much more "down" to go.
Agreed. I'm also on a SP3 (but the i5 version), and I wouldn't want to try doing serious work in a desktop environment on a cell phone processor.
Maybe things will change in a few years as ARM/Snapdragon/etc processors continue to improve and phones get more memory, but for the time being I think MS's approach to phones + large monitors is preferable.