When I built my house, I wired two circuits to a box near where the generator (3500 watt) would sit in the garage.
Then I installed 2 SPDT switches that you can get at the hardware store for around $10 each plus the cost of the box and outlets.
The two circuits powered the fridge, a couple receptacles, a few lights, and the entertainment system.
The majority of the time, the switches would be in the "Panel" mode.
When the power would go out, I would flip the switches over to "gen", plug it in, and fire it up.
It worked out great.
(I had a wood fireplace for heat.)