A tree with unique care needs. It loses its leaves in winter. It has unique pruning requirements, so refresh yourself on them before doing work. It can be a very robust grower, and extremely apically dominant.
Protect the root system from sustained freezing temperatures. Move trees into an unheated garage, shed, or cold frame.
Repot right as the buds begin to swell but before leaves unfurl. Comb out old soil and trim back circling roots.
Standard baseline rule: Water thoroughly when the topsoil looks slightly dry. Never let the rootball dry out completely.