upgrading over the max capacity question

Hey, I just got a 3rd gen drobo 4bay, and moved my diskpack from my 2nd gen drobo, all went well. but i was thinking, i have 4x 2tb drives, and in the drobo dashboard under ‘volumes’ it shows ‘max capacity’ as 16tb (because when i set up the original drobo, that was the max at the time)
but now there are 5 and 6 tb drives out there, so what if i were to upgrade to 4 x 5tb drives, which would be over the initially set max?
does drobo just nicely increase the size for you? or do you get stuck making additional drive letters and splitting the drobo up.
I do not want to split off additional drive letters,