I doubt Starfleet was considering mothballing ALL the military starships, after all, the Klingons weren't the only threat in town (unless the implication of the fact that the Romulan Ambassador of all people was sitting in on a STARFLEET BRIEFING implied that at the time of TUC relations with the Star Empire were far more cordial).
Starfleet has always been shown to be extremely short-sighted in their policies though. Putting families on starships due to their planned extended exploratory missions may have seemed a good idea at the time, but as the fate of the Saratoga
at Wolf 359 showed us, that policy did indeed return to bite them on the ass. From the Enterprise-E
and Dominion War, that policy seems to have been largely abandoned. The introduction of the Intrepid
classes would also seem to indicate that Starfleet was moving away from the idea of long-term exploratory missions, preferring many smaller ships undertaking shorter tours, than a few large ones conducting long-range missions. Even the Galaxy
class starships, despite being designed from the the outset for twenty-year+ exploratory missions and the flagships of the families aboard policy, never seemed to have strayed much from the Federation borders.