I had a similar question...
I pitched one of the WLP004 vials on Friday evening & it was 65 in my basement.
A 2" to 3" head of krausen formed for 2 days & now it's totally gone.
I can't imagine that the yeast finished its business on a 1.060 oatmeal stout, in that little amount of time, at that low a temp.
Can this be true?