As far as I know we have never seen that happen against a single target. I believe the reasons are operational not cost related. A single truck can fit like 5 shaheds. For 100 at the same target at the same time you need to coordinate 20 crews just to get them in the air all these drones need to be controlled to some degree as well. It's possible but we have not seen such an attack. We have seen hundreds of drones targeting hundreds of targets against an entire country. So it's definitely possible, but I wager it's harder than it sounds to send 100s of shaheds against a carrier strike group.

Shahed drones are very slow, and can thus be very easily distinguished from antiship missiles and can also be intercepted far befpre they reach the ships. You are thinking SM-2s. But the best way to deal with such a threat is a flight of f-18s with a bunch of laser guided rockets (like 50 or 70) and a targeting pod, intercepting the drones hundreds of miles from the target.