There is always one carrier going through major overhaul/refueling. That's a two year process that doesn't require an air wing.
As for the size, the old air wings had two fighter squadrons, two light attack squadrons of A-7s and a heavy attack squadron of A-6s. They now have 4 squadrons of F-18s so they can do more with fewer aircraft. Depending on the needs the carrier has 4 fighter squadrons instead of just 2. Or four attack squadrons instead of just 3.
No way does a Hornet lug as much ordnance as an A-6 used to. I'd tend to question that business about "more with less" -- more flexibility, maybe, but not more iron on the target. Plus, the A-3's went away, too.
I was aware of the overhaul periods, but I was always under the impression that the Air Wings had similar “down time” periods where they were in intensive training on land. I may have been wrong, but that was my understanding.
And when you said old air wing type, you weren’t kidding. The type I was familiar with had two squadrons of F-14s, two squadrons of F/A-18s and (I’m still fuzzy on this last one) one or two squadrons of A-6s. I think it was just one squadron of A-6s but I’m not sure.