Porcelain berry.

Don't plant porcelain berry unless you want the plant to end up showing up all over your property and your neighbors' property. This vine reseeds like no tomorrow once it is established. Used to have two of them and took them out just for that reason. On top of that, if you have issues with japanese beetles in your area, they will be drawn to it like a magnet. Been there done that.

Montanas are a vigorous vine but just like any other vine will take a few years to cover the walls of a house. The hardiness ratings for montanas vary from microclimate to microclimate but I know of several people who successfully grow them in zone 5 and 6. The main thing with montanas is that they may have their flower buds frozen out or the plants be frozen back down to their roots in those zones (so no flowers which sort of defeats the purpose of growing them) depending on the severity of the winters and the siting in the garden. You don't say why they don't make it or if they die, what time of the season they do die. They don't like waterlogged soil and need plenty of space for their roots to run. Just some suggestions as to why yours may not have survived.