We have done this several times with both Hebridean and Shetland sheep, but not any other breeds. Sometimes this has been at the other end of the age range from yours, so older ewes which have lost condition during pregnancy and milking, so we give them an extra year to regain condition. A couple of times we have not put a particular ewe to the tup in her second year, so first lambing at 3 - no problems at all. Again with young ewes which have had a year off there have been no subsequent problems, although we have made sure they get no extra feeding above hay and a lick over the winter.
I think it may depend on the breed of your sheep, as some breeds have more of a tendency to overeat and gain weight than others. Overall I think you will have no problems.
One year we were unable to lamb at all, so I lent all our younger (under about 6 years) ewes to a friend for that year, to breed for lambs for his restaurant. Perhaps you could do something similar.