So I think that with bottom heat and supplemental lights up north and at least 50% humidity you can make them go a few extra months. My guess why yours declined in the fall indoors is that roots got chilled outside at night and then lower light levels indoors added to decline.
The tubers can rot easily when cool and damp and then dry rot can set in in the dry pot too. I would say if half of tubers survive it's good enough. So give it a try.
