I do a 3 week cycle. I re-breed when the kits are 3 weeks. Then she has another 3 weeks with them and a week off before more kits. But I only re-breed if she is still in good condition and the kits are in good condition and starting to eat. I am also close enough to the 4 week mark that if my doe starts losing condition before she kindles, I can take the babies from her. I have taken babies at 5 and 5&1/2 weeks for that reason. I want my does to stay healthy. If I do have to take the babies off her early, I haven't noticed a significant growth delay compared to babies that weened at 6 weeks but I do want to give them as long as possible on her.
My does have all summer off because we are in Texas. It always gets too hot in the summer but seldom gets too cold in the winters so my does have the summer off plus however long it takes for the bucks to get over the sterility from the heat. This past year they were into Jan before they were over it.