Re. Grey wolves, it seems common place for packs in captive settings to maintain a breeding apir along with their offspring under the age of three years. A litter of pups are born and remain in the pack until at least the age of two, while the next litter is being raised.
Conflict can indeed arise as the offspring mature and a common solution is to split them into male/female sibling packs, which have a greater stability long term.
With this in mind, importing a 1.1 pair would be the best way to go, with two or three additional facilities willing to acquire surplus from the breeding pack as the wolves reach the state where they need to be transferred out.
Australia Zoo are another facility who might consider them since they had plans for a North American precinct.