My own (pretty wide and varied) experience is that as long as you don't (over)feed a ewe carrying a single lamb, and the breeding doesn't give horn buds, singles are usually trouble-free at every stage. (Even using a chunky tup.)
And that's a hard no to goats, thanks! Maybe if we decided to switch out of cows, but (a) there are too many of us love beef too much, (b) goats won't help clean the ground one bit, whereas if you have ponies and/or cattle, you really want sheep to graze to clean the ground anyway, (c) we live in a very wet place, and there's no suitable goat housing, and (d) if I can't get the delicate townie palettes to adapt to Shetland hogget, I don't think I even want to try with goat meat..!