Since losing a lamb to a badger (probably but not proven - we have a very active badger set on site and fresh tracks most mornings) a few years ago, I always bring my new families into a smaller enclosure at night time, still outside (my lambing shed has been taken over by the goats full-time.., so all sheep activity is done outside anyway.) but easier for them to pair up. I also feed in there, so the ewes are queuing up from 7pm onwards...
Not had any problems when the ewes are actually lambing, but mine a Shetlands - well suited to living and lambing outside. Not sure Ryelands are though... if they are very woolly on their faces, it helps to cut away some of their wool from their cheeks so it helps them to see their lambs and probably also any predators (I found that with the Bowmonts... forever losing their offspring)
When I have bottle lambs they tend to be in the goat field, and live in a pen in the goathouse, and will stay inside at night for quite a long time...
As pharnorth said - it helps me sleep at night...