You need to do your maths on this. Add up your needs, your power shortfall and how long you expect to be between mains power and then use:
- your gadgets need 3/2 the power injected them due to 5V/3.7V up/down shifting
- add a bit just in case.
If you didn’t tell me anything, I’d say a Powercore 10000, it would likely see you through long days between mains power.