We ended up using one of those giant Pyrex cake pans (it got the job done, but of course it's not the most aesthetically pleasing thing ever; probably individual ramekins would be better, especially since the caramel bottom made it so difficult to 'scoop'), and ended up with a lot of cake. Thankfully it turned out well, although it was far better once left to cool until it was just slightly warm, allowing the beer flavours to surface. All that said, this thing was incredibly sweet - an entire can of maple syrup will do that I suppose (good thing we got all those cans at a good price in Québec this past summer).
We served the cake up to a friend after a main of La Fin du Monde Salmon and Pearled Barley (that recipe was excellent), and it was a great way to finish the evening. That was also the evening all the snow started, which made this warm cake even better.
Tucking it away in a container in the freezer, we've been warming pieces of it up on select evenings for dessert. Sadly it's almost gone, so a new dessert is going to have to take its place sooner or later... maybe some good brownies.