As someone else pointed out, people often complain about Hallmark movies being all the same. I don't think that's fair, even though they do tend to follow a basic formula (there's only so many ways to tell a feel good love story). But this is not a typical Hallmark cookie cutter movie. The problems of divorced couples are rarely featured in Hallmark movies (former spouses tend to be conveniently dead). And there were some authentic well acted moments in the movie. That said, as a divorced father, I think it's wildly wildly wildly implausible that a divorced mother would ever agree to spend Christmas (and the days leading up to it) with her ex husband's girlfriend and her family, in their home, in another state (or that the ex and his girlfriend would suggest it- and pick that time to...). That kind of fantasy may work for Chris Martin and Gwyneth Paltrow, but not for the other 99.5% of us. Then again, with all the secret prince, amnesia, magical Santa, time travel stories, Hallmark is not exactly devoted to plausibility.
I like Amy Acker, Brooke Nevin, and Warren Christie, and there was good chemistry between Acker and Christie. But the ex husband Jeff was horribly miscast (not his fault). I don't see him being with either Acker or Nevin and I didn't see any chemistry between him and Nevin.
But kudos to Hallmark for trying something different and including a divorce plot line with both parents being around (instead of the convenient "my ex is out of the country on business" plot line). It was unrealistic, especially for those of us who had the opposite of an amicable divorce, but there's a lot to be said for promoting a post divorce life that puts the needs of the kids first. But that's easier to say then do.