We began overnight training earlier this week and it couldn't have gone better. The last two nights Colin has woken up once but cried for less than a minute (and only halfheartedly) and put himself back to sleep. He has also started waking up after 6:30 in the morning which is a much better time than 5:00.
Naps have been going well too. In the last few months Colin has started waking up too early from his nap and needing help to go back to sleep. Sometimes I could hold him for a minute and put him back down, other times I couldn't put him down, but he would fall totally asleep on me and not just be snuggling. So today when he woke up at his normal 1hr 10 min mark I waited. He whimpered on and off for about 3 minutes and went back to sleep. He ended up waking up after 2hrs and 45 minutes! Which is almost unheard of for him. He still didn't wake up happy, but he was holding his puppy when I went in to get him! Looks like he at least has a friend, if not a real attachment!! It just gives me something to bring with him from home when we travel to help transition him to new places.
Now we just have to work on ME sleeping through the night. To be honest I feel worse this week (as in more tired) than I have in a while, I'm not sure if that is part of the recovery or what but I certainly have not been sleeping as well as Colin has. I think it will take a while to recover from roughly 20ish months of sleep deprivation.
I expect set backs at some point. Our first big test will come when we travel for Thanksgiving, but since Colin is very used to my parents house I'm optimistic it will only take a little coaxing to keep him on a good path there.
So that is it. End of Story.