the G-man wrote:
Not the mention the fact that they are losing control of their own timeline. Unless Ted's kids are adopted they don't have much longer before he has to actually get married in order for him to have those kids that have been sitting there for the past eight years listening to his story.
They addressed this in last season's Star Wars episode. Ted will have a newborn daughter in the year 2015. Subtract 9 months, some time for the wedding, and "courtingship", and you're realistically looking at the end of this season as a dropdead point for meeting the mother.