Get Samsung Galaxy Note 3 or 4 instead. It's just a bit smaller than a small 8" tablet but as capable. IMO - Note is an ultimate survival computer, as it also allows you to get rid of a pen/pencil and a paper notebook, its Wacom pen is extremely natural for writing and drawing. Note 5 and 6 are not recommended as they don't have memory expansion slot and removable battery anymore.
I agree on a Samsung Note 3 or 4. We have one of each model along with an extra battery. Although I am tinkering with DIY longer range emergency battery backups for general use, including phone charging, I have also purchased an
Anker 26800mAh Portable Charger. Between the extra phone batteries and the Anker charger, with careful use in any short to mid-term power loss event, we have potentially a few weeks of battery life for the phones.
Also these Samsung phones have 32 GB of on-board memory. Coupled with each also having a 128 GB Micro SD Card, there is plenty of data storage capacity.