We have many households to "support" within our family. Basically, we celebrate for about 3 days straight. First there's the X-mas baby's birthday on the 23rd. Step mother (divorced) takes her out for lunch. Then in the evening, a family party Usually hosted by her father and the invitees are her step brothers, mother (divorced) and mother's family, so b-day girl's aunt, uncle, cousins. Christmas Eve starts out with Dad & step brothers, late Evening with Mom, Breakfast with mom, then off to step mother's by brunch time, and THEN to her SO's parents (thankfully still together) for the afternoon & Boxing day.
The key really is to segment the days and convince the secondary & tertiary families to play along. For us it's worked out well because everyone's preferred Christmas celebration times are complementary. We've applied this as us kids start getting older and just getting married. Never mind divorces, just all the in-laws.
Thankfully, our segmentation is going to work out, because my sister's serious BF is celebrating with us for the first time this year, and his parents usually do their thing X-mas afternoon, which will be after our family is finished with our usual morning celebrations.