I'm sure that in your climate, your mini standard will require some winter protection. You could keep it in the container and sink the container into the ground for the growing season. When it starts to freeze, you will need to move your tree into an unheated building or contrive some way to protect the graft union (where the rose variety was budded onto the root stock stem) which is the vulnerable part of any grafted rose.

All of my tree roses are grown in pots which are winter protected in an unheated garage, where they are moved outdoors in late winter when danger of a freeze has past.

If you experience prolonged freezing temperatures where you live, your tree will definitely require some winter protection.