Ours was cut right back when the house was painted. It has now grown to its previous proportions. Give it time.

It's perhaps a little early. It takes a lot to kill a Montana, so I would be surprised if it didn't recover, however you may find a lack of flowers as Montanas flower on the previous years growth.

Thanks ,will see what happens.

there is no sign of active growth on my Montana so don't worry. It will produce growth from buds below the soil level.