Laura, at that age with LO2, I'd always do the CN as a sling or buggy nap, as I figured it was on the way out anyway. So we could always go out at the time. Another thing we did was if LO2 woke early from a nap (often!) in the AM, I'd get her in the buggy and head out and she would drop off again, so avoid OT and get a cot nap (sort of). Can you mix up your ways of carrying him as well? If you mix buggy/sling/carseat, perhaps you'd get enough sleep? Does your buggy need extra darkening perhaps? Also, I think a short AM, loooong midday, plus a CN could be a good enough pattern for some days, no? I'd be concerned only if he wouldn't sleep at all.
I think maybe you could plan to mix your days up? Have an at home for naps day, and then an out and about day?