It's not something I'd attempt, ever, but if you want to give it a try, from now onwards during winter - while its dormant.

Why not try taking some cuttings as insurance? You will probably want to prune it to reduce the strain on the roots anyway. I try to remember to prune roses at this time of year to reduce wind rock.

Definitely the cuttings route. As young plants roses are movable, but old ones don't make a root ball, and resent the move. They are weakened and become prone to disease (even more than usual!). Phil