If the paddock you are wanting to move them to isn't too far away, could you just open the gate/s and then let them move through at their own pace. When they have all moved into the fresh paddock (after a couple of days) you can lock them in there.
If the paddock is a far way away, it isn't ideal, but if you took them really slow it might be Ok.
Really, it's just a hard season to be lambing ewes. Good luck.