Dr of BBQ
Who ever told you that is wrong you have room to spare. Is your truck plugged in at home at night? If so your coolers and freezer are both at temp. And your GE water heater ( electric ) is hot. Now if everything were off for 12 hours and you fired it all up at once you’ll have a surge in power usage, but you should still be ok, close but ok.
Who ever this person was didn’t know your total amps usage or something. Was it just a guess on his part? I think your worried about nothing although lets see what others think.