re: Satsuma recovery(from cold) - died, need to replace

let the suckers grow from the rootstock for now, then in late winter collect some equivalent-thickness donor branches (scion) from a friend or neighbor of whatever citrus you want to grow (or more than one!) and graft onto your rootstock suckers.

Plenty of great tutorials on yutube. A razorblade and rubberbands is all that you really need, though a roll of paraffin tape is handy to keep the scion and joint from drying out before union occurs.

You've got a head start in the old rootball and can create your own tree.