I live in Michigan and the ground will not be frozen till Januarty. So once dormant they could be sent. If after January, yeah March would be fine. Yes only bare root them while dormant. November is a good month and so is March. Either those two months would be best. After November the plant has little time to adapt.

Spring or fall when most leaves have fallen is fine- you can strip the last leaves off if you like for an earlier fall transplant.

Wrap the roots in plastic bags filled with a moist but not soppy material- shredded paper, sawdust or peat, something like that. Tape the bags tightly around the roots. Then wrap the whole shipment with thin plastic sheeting by lining the box with the ends hanging over the sides of the box. Wrap it up and close the box.

Here in southeastern NY I transplant bareroots until the ground freezes and most species do great even when moved late Dec. Currants are especially easy, with blueberries it depends on how much root you can dig up and how much energy was stored in the plants this season. It is not really worth moving weak growing plants, IMO.