Well, last year's team had a skid in med February, too.
Most folks thought they would win fewer games in the regular season this year, not so much due to Posey's absence but because 66 wins is just so hard to achieve. They're on a pace to win 62, although I expect some losses on the upcoming February trip plus on a shorter stretch of away games in late March. So 55-60 seems about right.
The real issue is the playoffs. Posey had some big games, and others will have to step up instead.