I was lucky enough to find a lightly-used Surface Pro 3 (i7, 8 GB RAM, 256 GB SSD storage) with 2 pens, keyboard (or whatever Microsoft call it) and full-sized dock for less than half price. With a 128 GB micro-SD card, it gives me 4-6 hours of battery to do the 'serious' stuff which, in my case, is photo processing (Lightroom 4,ON1 Photo 10, Photoshop Elements) and music making (Presonus Studio One, Ableton Live 9.5, Komplete 10, etc). Plenty for my needs, and it slips into the skinny laptop compartment of my rucksack with room to spare. (It actually also fits into the map pocket of my gilet, but that's another story). Also in my rucksack is a small, lightweight Bluetooth mouse for when the pen and/or keyboard aren't enough - it doesn't get a lot of use.
In my pocket is an 8" Acer Windows tablet which also gives me 4-6 hours of 'consumption', including G+, Twitter, web browsing, maps, train and other transit times, magazine and book reading, etc, etc. It has 32 GB of storage space (plus a 64 GB micro-SD card) and 1 GB of RAM. As it's an 8" device, it runs full Windows 10 desktop.
Out and about, they connect to the net (and so to OneDrive, Dropbox, etc) via my 10 GB per month 4G to WiFi dongle. At home, they're on the same Workgroup as my PC, so I can drag and drop files between them at LAN (the Surface) or WiFi (the Acer) speeds.
This combination of two tablets serve my needs very well. Perhaps the OP might consider this solution.