The energy that went into building the branch would have gone to producing additional biomass above the graft that wouldn't need to be removed, had you removed it immediately. Yes, remove it now.

If the plant is hardy to your zone, you'd be wise to bury the container against the north side of a building where it will be protected from winter sun and wind. Placing the tree in a basement after leaf loss will interfere with the tree,s dormancy mechanism. The tree needs a certain amount of time at temperatures between 32-45* F. to release it from dormancy. After this chill period, the tree passes unnoticed into a quiescence or quiet period in which is rests as long as the soil remains below about 45*, but it is fully capable of growing with full potential vigor as soon as it sees several days of soil temperatures above 45*. In other words, your tree will begin to grow because of the warm temperatures, and because it was deprived of the cold rest it needs, will likely suffer badly or die in the upcoming growth cycle. You can trump the dormancy cycle with warm soil temperatures, but you cannot change the trees desire to have a cold rest.

You don't want the tree leafing out in Dec, because it will suffer horribly indoors from bad light & low humidity. You'll also need to prune off all or most of the growth that would occur indoors because the long internodes and weak branches will not fit the trees normal growth pattern & would likely destroy its form.

You might be able to get away with growing the tree indoors under halides or HPS if you can keep humidity up to 60% or so, but why struggle & cause the tree to struggle when it's unnecessary?

Al

Thank you, Al. I'll bury it today after I prune the branch. Anita