They are probably as hardy as a Russian Olive and you can honestly out and out abuse a Russian Olive and still have it survive. However, the foliage is the problem with these shrubs, not the availability or the ability for it to survive. In fact, I'm going to do an experiment with my Russian Olive and leave it sitting in a grow box along a hedgerow this winter... I have little doubt that it will survive with no winter protection other than the box sitting on the grass.
They are so prolific though, that if you managed to get one shaped into a cascade and entered it into a show, by the end of the show it would be a formal upright, with a really weird trunkline. I think I'd dig out a larger Russian Olive and let the kids have a go at it before I bothered... you'd be doing the environment some good by digging it up and you'd quickly realize what I mean.
However, these shrubs are hardly endangered or scarce, so digging it up in the spring like any other tree shouldn't pose a problem for you at all.
BTW, I see that you are always on the hunt for trees... if you don't know already, be aware of hawthorn bushes... one scratch in the eye and you WILL be blind for life in that eye. Worse yet, one of your children could get tangled up in one if they are chasing each other around.