Right after holiday cacti finish flowering they usually go into the doldrums for a while until the days start to become noticeably longer. During this period they should not be repotted, fertilized or watered as much as usual.

Your different varieties can certainly be potted together, but wait until late spring when they are grwoing vigorously before disturbing their roots. It is also important to squeeze them all into the smallest possible pot so that you don't have too much excess soil that retains moisture. Overwatering is death to these plants.

The repotting will probably disrupt the flowering cycle for next holiday season.

BTW, these plants are not "forced." They require short days and dark, cool nights for about 6 - 8 weeks in the fall to bloom. This is part of their natural flowering cycle. Without it, they are not likely to bloom until they are much older.