I have 3 huge, beautiful Christmas cactuses that probably have been in their pots 5 years if not longer. They are too heavy for me as they are. Can I trim off a lot of foliage back to pot rim which will lighten the plant, therefore making it easier for me to handle, remove plant, remove as much old soil as possible, & repot in same container with new soil? The containers are 10" across, so you can see what huge plants are in them.
You are right that it is a good idea to repot your holiday cactus and now is a good time to do it. Here is an article that covers how to prune and how much you can remove without damaging the plant's health. https://www.gardeningknowhow.com/ornamental/cacti-succulents/christmas-cactus/christmas-cactus-pruning.htm