I just came back from 7 days away and i was travelling for 4 of those days, the 3 days that i was 'camped' i was dry camping. I used the generator during the day when needed and used the battery to run the furnace at night. I will add that prior to leaving on this trip i bought a new deep cycle battery (my compartment for the battery is not big at all and it would be a tight fit for two batteries). I had no issue with the house battery handling the furnace at night and was fine in the morning. Granted it was not as cold as when I had issues before but I believe buying the new battery helped/was needed.
I must admit when it comes to batteries i really don't have a clue on what i am doing. I have winterized my RV and it is gone into storage, i have removed the battery and brought it home and i plan on reading up on what to do during the winter with it (trickle charge?)
Thanks for all your responses, i am still reading some of the information provided.
Carol