Has anyone kept an elephant ear as a house plant?

I have, and it's been a ride. I have a lot of natural light in the room it's kept in, so it did ok-ish in the winter, usually around 1 new leaf a month, if I was lucky. I'd move outside in the summer to it's favored dappled sun and that cycle seemed to do OK.

Best thing I can say is: they're hardier than you might think. Keep them watered well, for that size I'd upsize the pot immediately, and plan on doing at least a gallon per week in the winter. Plant them in a container you can absolutely soak and catch the run-off.

They appreciate ideal conditions but like I said they're pretty hardy as long as you keep them outside of their freezing temps, they're one of those plants that live mostly in their roots, the leaves are just for utility.

edit: wanted to add: that room already looks good for over wintering (assuming it looks like that for a few hours a day)

I keep mine inside in the winter and on my front porch in the summer. I put it in a room with low traffic out of direct sunlight. Mine do really well when I mist the leaves with water once a week but I water it every other week.

I have a small one that I kept as a houseplant over winter and it started to fail because it wasn't getting enough light. So you may want to put it under a plant light through the dark seasons.

I've had one for like 3 months now and it's been great. Even started blooming recently. I keep it near a large west window and water every 3-4 days.