Your automotive type incandescent lamp bulbs will draw 1 AMP each @ 12VDC... The 35WATT TV set will draw around 3AMPs each hour @12VDC... Your RV trailer will also have a parastic drain of around 1AMP per hour. So adding all of that up for 2.5 hours gives you around 13AMPS for the evening.
If your single battery is a GP27 (105AH) it should produce around 13AMPS for 350 minutes or 5.8 hours...
If your single battery is a GP24 (85AH) it should produce around 13AMPS for 280 minutes or 4.6 hours...
Of course going for the full 5.8 or 4.6 hours will drain your battery down to 10.5VDC or 0% charge which you don't really want to do. You want to not ever get below 12.0VDC or 50% charge state so that will cut those two reading in half.. So you really only have 3.0 hours using the GP27 battery or 2.5 hours using the GP24 battery. If you drain out your battery to 0% charge or lower each day before re-charging it may start doing damage to your battery cores.
Spreading that out over your 3-5 day camping trip will result in a dead battery if you pull 13AMPS from it each night. By replacing the 13AMPS with your single 80WATT solar panel during the high SUN Day will put back around 5-6AMPS per hour so that may replenish it all back for you as you can probably count on 5-6 hours of high sun each day.
All of this is somewhat hypothetical but gives you an idea what to expect. You really need to watch your 12VDC battery level and when it drops to 12.0VDC go disconnect the negative terminal until you can re-charge it somewhat. The other downside of just re-charging alittle at a time is the battery will not ever get back to its full performance state unless you re-charge back up to the 90% charge state each time. Continuing to do this will also start doing internal damage to your battery. In other words the first time using your batter it will produce lets say 25AMPS for 140 minutes (or 2.3 hours) then you run it down to around around 0% state of charge and only re-charge back up to 50% or 60%. The next time you start using the battery it may not give you 25AMPS for 140 minutes since it wasn't re-charge back up to the 90% state of charge level. It may only give half of that number etc... Then you get it down to 0% charge state in just an hour or so of use... All of this will be very hard on your battery internal cores.
I am just saying it is not all that difficult to make it successful for you with some planning. Once you do this this then you never have to worry about running the battery down below 50% charge state. Doing what you want to do will not be successful for the 3-5 day trip and mark my word it will get dark on around 10PM at night when it happens haha...
Go read up on how the big battery guys do all of this with solar panels....
Lots of great info on the RV NET forum where I usually hang out...
You already have a 80WATT solar panel and a 1KW generator so just add a couple of 6VDC golf cart batteries in series, replace all of your automotive type lamps with LED lights, replace the converter/charger with a 45/55AMP smart mode converter/charger perhaps the PD4600 or 9200 series. Plan on connecting the trailer shore power cable directly to the generator main receptacle using a RV30A-15AMP adapter so your on-board converter/charger will re-charge your batteries in a quick three hour generator run time period. If you really wanted to get serious of just using the solar panels than you will need to get around 15AMPS coming from multiple panels and this may get your battery bank back to 90% charge state before the high SUN drops out in one day.
Don't forget your trailer is also your lifeline at home when the power mains go out... Not just for camping hehe...
Roy and Carolyn
I claim Horse Creek Country in Southern Ill - Momabear is from North Texas
We live in King George VA
RETIRED DOD DOAF DON CONTRACTOR Electronics Tech 42YRS
"We're burning daylight" - John Wayne
2008 STARCRAFT 14RT OFF-ROAD POPUP with PD9260C and three 85AH 12VDC batteries
2010 F150 FX4 5.4 GAS with 3.73 gears - Super Cab - Towing Package - 2KW Honda EU2000i Gen
K9PHT (since 1957) 146.52Mhz
"We always have a PLAN B"