In one embodiment, a device in a network identifies a routing domain migration candidate node in a first routing domain that is in range of a second routing domain. The device determines that the second routing domain is able to accommodate the candidate node sending traffic via the second routing domain. The device determines that the candidate node should send traffic via the second routing domain, based in part on a determination that the second routing domain is able to accommodate the candidate node sending traffic via the second routing domain. The device causes the candidate node to send traffic via the second routing domain.