If we exclude heating/cooling devices and electric vehicles, in a modern homes there is almost significant load.
Most devices consume up to 100W - computers, LCD-screens, fridges/freezers, fans, lights, speakers.
With 11kWh storage, that's 100 hours of 100W load (some losses).
Anything that makes heat (stove, AC, radiator, microwave oven, kettle, laundry/dish washing machines,
dryers) consumes around at least 10x more. And older bigger vacuum cleaners.
So in case of unknown period of grid failure, it is reasonable to stop ALL heating appliances.
Microwave oven is the only reasonable appliance to cook small portions of food.
Stand-alone kettle is fine for making water for coffee/tea. Make only as much as you drink immediately!
There is no excuse to use AC. And heating with resistive elements is totally useless, it will drain whole
Powerwall within few hours. Though not heating blankets.
PS: incandescent bulbs are thermal appliances as they are better at making heat than light