Whole house generators have been around for a long time and they are usually wired, at the junction, into a few specific lines to essential appliances like refrigerators because it’s hard to produce as much current as the grid on your own, and you want to spend what you can generate on site wisely. Trying to power your whole house through some bedroom outlet is not going to work well. Your TV will sit there sucking some of that power listening for your remote to turn it on while your lights will flicker and your fridge will chug chug chug and not stay cold.