Hi guys, I know that I'll be advised to avoid the plant entirely, but I'm not inclined to heed those warnings :). I would, however, like to minimize the invasiveness of the beautiful vine. Should I just plant this in one of those 50 gallon tubs without dranage?

I don't think you really intend to drown the vine....
Planting in a tub does have merit, though... Maybe place the tub on blocks...

The hard part is going to keep up with all the adventitious vines that are going to be growing from the roots, and attempting to escape the tub....

Once any of those extra vines touch the ground, they root.
Once trumpet creeper vines root... That's when the trouble starts.

I'd like to do something like this internet pic one day with trumpet vines.