I dont know what else to tell you. One of the things that Imps do in the house is get leggy. It is a bit of a shock to them but they should adjust but dont expect them to look the way they do outside. They like the shade but living in a house is like a cave to them. Just keep them alive long enough to get them back outside in the spring.

Alright. Other than being leggy, it doesn't look particularly bad or anything. It's actually blooming again. Should I pinch it back at all indoors, or just wait till it goes back outside?

Also, the leaves are forming these weird, clear, sugar-like droplets on them. It looks like guttation but that should just be water. They don't seem to be coming from any pests, either.

When I was a girl, Mom had the most amazing impatiens plant that was a houseplant--or should I say, a housebush? It was in an old 5-gallon creamer pot, and all she ever did was water it and leave it in a south-facing window and it was always blooming. It wasn't until years later when I saw impatiens used outdoors, and they were low-lying (compared to Mom's 12-16" stalks) so I almost didn't recognize them.
However, I will say that when the sugar-droples formed, it was invariably due to spider mites, especially during the dryer months of winter. They were hard to see, but they were present, and one year they took over the entire "garden" of plants in the south-facing window. Keep an eye out for the little buggers!