Pink Trumpet Vine (Podranea ricasoliana)
is a sprawling or trailing vine said to attain heights up to 20 feet while the Queen-of-Sheba Vine (Podranea brycei)
is said to get to 40 feet in height. I have/had a P. ricasoliana in a container (I'm not even sure if it's still alive.) Mine was nipped by frost one winter but survived just fine. I never pruned my vine, it was growing attached to a trellis and grew to about 7 or 8 feet tall. If you want to prune your vine to control it's height/size, I'd think the time to do so would be early in the growing season before buds set.
Hopefully others who grow these beauties will be along with advice and suggestions.