I did a Belgian Strong last year, OG ~ 1.081, extract-based, Wyeast 3787. I racked too early (after 1 week), and it shut down (or seemed to)--was at around 1.030, I think (but tasted good). The ferment did get up into the high 70's or maybe 80 degrees. Homebrew store recommended alpha-amylase, which worked (got down to 1.009, I think), but then it was too strong. Hangover city, now, although it tastes good. And super-foamy. Wish I had just left it in the primary a week or so longer. Also, temperature may have been a factor (I will only brew a strong Belgian in warmer weather, esp. with that yeast).
Anyway, sounds like you got some good advice here and are doing the right thing.
Anyway, sounds like you got some good advice here and are doing the right thing.