Put the HVAC fan into continuous run or circulate mode. A fan like that should be above 200 W.

If you have an electric car, set it to charge at night at lower power levels so that it takes all night to fully charge

You can leave a bunch of LED lights on, probably 20 to 25 with minimal risk. The LED outdoor strand lights are usually about 40 W total power strand

Dont have that many and would be too much light, but thanks.

Running the fan wouldn’t matter too much. But years on end, yes. You want something that is low great, but reliable. Sound like a motor is ideal. A box fan is cheap and draws about 75-100 watts depending upon size. Maybe you can run a couple in a different room. Low cost. Useful to have around if you need them

Or three smaller ones?

Like a desk lamp or something? I assume all my fixtures are for LED bulbs.

Just make sure to check the capacity of the socket. Many table lamps and such tell you to not go over a specific wattage, like 60. In that case you need more lamps. If there's a good hardware store nearby, they might be able to help. In fact, you may want to go see them up front just to be safe.

Doesn’t have to be a heat lamp, just a couple 100W bulbs. Probably some kind of fan could work if you could measure it’s amps but not many people have an ammeter laying around.

You will need a small battery charger, rated for a few hundred watts on a trickle charge.

Use the battery on an inverter to run something during the day.

You might need more than one battery to take longer to top off.

power unit where I'm guessing you want to be near to see what is happening while connected to the TV or lights in the garage or outside (for the LEDs, not the TV)?

Motor driven things like humidifiers vary their usage depending on whether the compressor is on or off so you want to use resistive things. Best bet would be to run the extension outside to two old fashioned 100W bulbs. You can buy the bulbs and ceramic bulb bases for a few dollars. Those same bases can be used for LED bulbs.

Ceramic bulb bases and 100 watt bulbs sounds good and cheap, not sure how to search that on Amazon or wherever though. I get kinda confused when it comes to light bulbs and the size of the base and the fixture I would need.

is standard for most lightbulbs. The A19 vs A21 commonly seen are the height of the bulb, not the base size.

From https://lamphq.com/a19-vs-a21-bulb/]

After my gas stove conked out, I've been making do with a Cusimax hot plate - has a dial setting the goes all the way from "1" warm to "8" and "Max" which would be way way over 200 W.

And an Instant Pot (the Keep Warm setting might be enough).