All depends who we're fighting I guess
it's unlikely we will be able to afford to have them constantly at sea on stand-by waiting for something to happen - much more likely it'll be a Libya/Gulf War type operation .
We'll know who our allies are, what they are providing , what fixed base air cover there is and the threat level. Given the last 25 years of operations air cover is going to be minimum and strike capability much more important - probably only another Falklands War would see us requiring the opposite balance of capability