So, I started racking my brain... What happened around the time that we went to North Carolina???
The answer??? The weather turned warmer and we did away with his Halo Sleep Sack! Could that be it???
Let's see! It got cooler and I decided to put him down for his nap in the sleep sack (swaddled with arms out as we'd been doing since he was 4 months). You know what? It was lights out without a peep and he slept for a good hour and a half without moving an inch. WHAT?!?! This has to be a coincidence!! So, I used the sleep sack for the rest of his naps, and bed time, and the next day's naps and bedtime.... sweet sweet glorious calm baby is back.
Do we have sleep-crutch on our hands? Quite possibly. Do I care?? HELL NO!!! If this helps my little one get the sound sleep he so desperately (and I so desperately) needs, so be it!! Bring on the sleep sack!!!
If anyone recommends a light weight one that still swaddles but is a very thin breathable material - I'm all ears!! I don't think the one we're using will work when the sweltering heat comes back...