Bought 3 pots of "hot chocolate" calla lily from big box store drastically reduced; at that time, about half the leaves were snotty/slimy but half were looking nice. Since then have lost nearly all leaves, but it's been chill in the evenings here down into the 50s. I've never had callas before, unsure what was normal and what is disease.

There is new growth in some places but all eventually gets slimy and falls off. Due to rain and my watering habits the pot never completely gets dry. I had plunked one whole pot (several plants) in a larger pot with more potting soil without prying the original apart to see what the base was made of, and today I finally did. There had been probably 7 or so bulb-y items; of those, 4 were very mushy and foul-smelling on my prying, and seemed quite dead so I pitched them. Of the remaining 3, 2 had slightly mushy spots but some new growth and plenty of roots and 1 had no apparent mush so I have put those 3 back in the pot and brought it inside (in case slugs have been visiting, as I do see trails) - this pot I have not watered yet.

Sooooo, any suggestions, ideas what I am dealing with, and what the chances are that any good will come of the remaining 3 bulbs? Should I put the pot in the basement and let it dry out and overwinter, or will doing that with roots on it kill it so better bet be water it and try to overwinter as a houseplant?

Thanks in advance.