Proofing dough in another appliance - crock pot?

proofing chamber is a microwave oven with a container of warm water inside. If your microwave is large enough and has good enough insulation, this works pretty well: with some practice, I can keep a consistent 25 C temperature, plus the humidity doesn't let the dough dry out. Try it!

If i need some extra help temperature wise I usually turn the oven on for a minute or three, make sure its not too hot and proof in there, with the loaves tented in a damp towel.

Another vote for the oven! My house is even colder than yours, I heat the oven on 200c for one minute only. Turn it off and put the dough in along with a jug of hot water. I top up with another minute on the oven and a fresh jug of hot water every 2-3 hours. It stays nice and warm in there. Then I use my cold house to my advantage to retard the dough over night, and bake in the morning. Like Mr TT I like the humidity the jug of water adds.

pad with layers of kitchen towels on top to regulate the heat to 82 F when the pad is on the medium setting and cover with a towel.  Seems to work OK.

I also use a heating pad but on the "Low" setting. There are various pieces of tile or towel placed under the dough bowl depending on the temp I want to maintain. This usually works quite well but it can go wrong if I don't pay attention (see my latest post).

This works to incubate yogurt, keeps a container at 100-F, it would probably work to proof starter. Place jar of starter on top of crock pot to keep it warm (A crock pot heats the food, internally, to about 93°C (200°F) on LOW, 149°C (300°F) on HIGH) .

Fill the crock pot half full of water. Place temperature setting on LOW. Put the crock pot lid in place, up-side-down. Place a folded dish towel on the up-side-down crock pot lid. When crock pot heats up, place covered bowl or jar of starter on the towel. The rising heat should keep it warm, but not too warm. After the starter warms, take the starter temperature. If it's too low, turn the crock pot to HIGH. If the starter temperature is too high, add another folded towel or two under the bowl.

Crock pots are made to run for hours and hours like what's required for the task here, digital models have timers. Some models have WARM, LOW and HIGH settings.

before you need to proof, empty it and put your dough inside and close the door.  :)

I have found that keeping my interior oven light on at all times maintains a temperature of around 80 degrees F. ( +\~ a degree or two) I use this technique to rise bread or speed up my levain's ripening with no need to turn the oven on and off. My oven does have 2 lights though, so it might be warmer then an oven with one light. Hope this helps.

Seed germination mat, digital thermostat controller and plastic cake holder big enough to cover bowl, banneton, starter, . Works almost too well.