Great answers above, but I wanted to add something about the cheating that I've adjusted with great results, as in I am not cheating at all yet.
I do not like the idea of planning to cheat. Look at it from a legal standpoint. A premeditated crime is worse than a crime of passion. Repeated premidated crimes get the label career criminal. I understand cheating is going to happen and shouldn't be compared to car theft, but I think it should be more in line with a crime of passion. Stick to your low carb plan with no premeditated schedule for cheating. Cheat when a situation arrives like pizza with friends, or someone brings amazing danishes by, or you find yourself famished and staring at bagel fresh from the oven somewhere. Then don't punish yourself for cheating. It's just part of life, not a planned part, but sometimes carb happens.
ymmv