12V furnace/heater/blower run time?

Just ordered a Neo nsvr. Getting it well loaded…insulated… Windows…etc. This will be used as a camper/toy hauler/ice house. Question comes regarding 12V blowers for the furnace and led lights.I can run the numbers and get a estimate of run time. But that is rough at best. What sort of real world run time are you guys getting out of a standard deep cycle. I know there is variances per rating. Just trying to get a idea. Or ideas on the route to go and expected run time per what your using. Any words of advice… Options to consider…etc? Just want to make sure I do it right the first time.

Depends on outside temperatures.

In my Firebrand fish house I have gone 4 days with tandem 31 series deepcycle batteries with still alot of reserve in them. A generator was on my short list, but not really anymore.

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I have a home made wheel house. I would say it is comparable to a 17′ Ice castle, but built better. 2″ foam board in the walls, r 13 rolled in the ceiling, 1.5″ of spray foam under the floor. The inside is 7×14 with a 3.5 “V” in the front. I run a 20,000 BTU forced air Furnace, 12v LED lights, 12V TV/DVD combo and I can run for two days with the tv on most the time. A lot depends on how cold it is out side. -23 and the furnace runs a lot. At zero it runs three times a hour. I have three windows that and thermo pained. I used fanfold for sheeting and then used house rap over that. The house is pretty tight. The next one I do is going to spray foamed all inside that will make it even tighter.