My mum's had a dracaena (unsure of specific species) for ~5 years and it was doing great. However, she was insistent on keeping it downstairs and our cockatiels eventually ate the majority of the leaves off of it. She gave it to me to attempt to revive but im not really sure where to start. the two stems with no leaves on have already been pruned back 6 inches or so to try and promote new growth. However, the stem with leaves that I was trying to hold on to has started turning black and the leaves are wilting. I'm assuming this is stem rot and I should prune it as well but any confirmation would be great. On top of that, the plant seems to be pretty rootbound and looks in need of a repotting. However, covid is making it somewhat difficult to get hold of a larger pot quickly and I was wondering if pruning the roots and repotting in the same pot would work as a semi permanent measure? And if so how to go about it. Any advice would be great as I'd love to save the plant. Thanks. I've attached an image of the plant and a close up of the stem in question.