I've brought my own towels before when my hair was really long. Beyond that, I haven't usually needed extra. (And I'm usually a two full size towels kinda girl.)
One bath size and one hand towel size (rectangular). I have never felt the need to ask for extra here and in hotels, I always need more! If that helps.
you get one large and one very small towel upon entry. yes, you can ask for extra, I've received one extra in the past.
Thanks! Your answer is awaiting moderation.