With the Honda the 12v charging is low amps and will take forever.
Plugging into the 7 pin on the truck is low power and takes forever.
Before we go on a trip I do use a stand alone charger at home at 12 amps for 2-3 days to fully charge a battery. Actually I do it as soon as we get home and then a day a month and right before we leave. It is a automatic charger.
When I use a generator while camping I plug the campers power cord into it and run it for 2 hours. That will let the campers on board converter charge the battery up to 90%.
We have also turned the truck around and connected heavy jumper cables to the battery and started the truck for a hour a day. That's gotten us thru a week of needing the furnace at night.
We also have solar but for a weekend we will leave the solar and generator home. A well charged battery will allow us 3 days of use including fridge, led lights, pump and furnace at night. I have left the fridge on in the lot for a week before and it was still cold when I returned.
So first have your battery checked to make sure it's good. Second make sure you are getting a full charge before you go. Third is a second battery. If the first one is new then you may be able to pair it up with a like battery. Otherwise two new 12v or even better two 6v should have no problem running your fridge for a week if properly charged.
You could get a solar power mounted and it not only can replace your daily needs but also have the battery nice and charged when you want to go camping. I'd think 120w mounted flat on the roof would do but others here are better with the specifics.
2011 GulfStream Amerilite 25BH
2003 Ford Expedition with 435w tilting portable/ TS-MPPT-45
750w solar , TS-MPPT-60 on the trailer
675 Ah bank, Trip-lite 1250fc inverter
Sportsman 2200w inverter generator