The simple, but maybe awkward way to achieve this is to power your gear off a car or portable sealed lead acid 12 volt battery of sufficient size connected to a 'true sine-wave' DC-to-AC 120 volt converter capable of powering all your AC connected gear in the field.
These special purpose True Sine Wave output converters are made by several manufacturers, and some are sold with internal batteries for UPS service for computer/audio sensitive equipment powering.