What length to use for campgrounds max? With or without TV?

Depends on the fine print in the campground information. SOME tell you the driveway length and in that case it would include both the TV and the trailer. Some give you merely a number but I'd recommend you consider if you really want to camp somewhere that tight. If a couple of feet make the difference between getting in or not then I'd opt to NOT (camp there). Check into public campgrounds like NFS, COE or BLM where land is not that tight and spread out and relax a bit.
Good luck / Skip