British Columbia: Moving tree peonies

It looks like we will be moving to a smaller house and garden sometime in the winter. We have several tree peonies we'd like to take with us but we are uncertain about whether they will survive the move. Three are quite large (4.5' tall and about 2.5' around) and three have been in the ground two years so are only about 2' tall x 1' wide.

Can we pot them up now to move them later, or is it better to move them in one go? How much soil should we keep around the roots? Is there anything special we should do to give them the best chance possible?

Thanks in advance!
keke