We go dry camping for two weeks every year. We do have a genny but I run it every three days to fully charge my two 12V AGM Group 31 batteries.
We do not use the furnace and use lights only at night when getting ready for bed. The Fridge and stove run on propane and we remove 1 light from every fixture to cut down on power consumption. I may be able to stretch it to 4 days but I wouldn't count on it. We are very power frugal when we dry camp. We don't shower in the the RV since we only have tank water and we only use the toilet at night to avoid filling the holding tank. We brush our teeth at night and that is the only pump usage as well. It still takes 6-8 hours of charger and genny to fully charge the two batteries.