And hey, the Patriarch might say "bugger that edict" once the Schism occurs, so concievably you could have many Europeans convert to Orthodoxy because temperence is not only killing them, but making life far less enjoyable
Considering the fact that, the OP is positing a ban on alcohol right around the time of the Orthodox-Catholic split, it's entirely possible that we end up with the East not going along with this papal edict. Alternately, it occurs to me that a ban on alcohol might be more popular in the East than the West; it wouldn't be the first time the Eastern Church had co-opted bits of Islamic theology (iconoclasm springs to mind).
In either case, it's going to be difficult to gain much support for an all-out ban on alcohol; it's entirely possible that any such edict would simply be ignored, similar to edicts against all the other social ills the Church regularly denounced. The Church can certainly ban alcohol for the clergy and denounce it as much as they want, but the secular rulers won't go along with such a ban without a very good reason. Considering how important alcohol was as one of the few pleasures the average serf had, getting rid of it is going to mean a significant increase in peasant revolts.
Assuming the ban does go through, missionary activity in Scandinavia and the various pagan tribes in Eastern Europe is likely to take a hit from a ban on alcohol; relatively recent converts might turn apostate at a new major restriction, and it will hardly make Christianity more appealing to Prussians and Lithuanians.