Yes, for that specific example.
For discrete things like going to the theatre I'd take the "ever" as implied or even unnecessary.
With a variable thing like eating "hardly" and "hardly ever" are fairly different:
"Hardly eats" vs "Hardly ever eats" => "doesn't eat very much" vs "doesn't eat very often"
In the first example the total amount of food eaten is small but there's no comment on frequency and in the second there's a long time between meals but no indication of how large each meal is.
But for binary things, like going to the theatre, they mean much the same thing. This is because you can't go to the theatre "a little bit"; you either go or you don't. As such having a low total amount of visits to the theatre and not visiting very often are the same.
Or at least that's my perspective as a native speaker of British English.