Yeah you need to be more specific: there are many inverter discussions on the forums here so either search around or detail what exactly you want to run off of the inverter.
When we hunt we run out of battery for the furnace. We have ACE 30'
30.1? 30.2?? 30.3???
I don't know what you think an inverter does, but adding an inverter will only shorten the time until you "run out of battery for the furnace".
Either start the generator to charge your batteries, or if you want to remain stealthy get a solar charging package, which may not work if you are in the woods in the shade.