I think they are good to about 0F or outdoors in usda zone 7 with some root protection (e.g.,, mulched over on the ground or set in the ground).
Winter hardiness is affected in plants by the pattern of deepening chill (overnight) that naturally happens in fall. So, I think
@BonsaiGuyNJ needs to take it outside in the afternoons for a week, say. Then in the mornings. Then leave it outside. Embed it and/or mulch it in to protect the roots, if temperatures are forecast to drop below 15F, or put it in the garage overnight.
Light levels indoors are about the same as deep shade outside. Heated interior air is very dry compared to the humidity outside.