you are probably ok. i go more by what they have filled, than by what they have built, although the two are usually closely related because they build what they will use.
i think finsky is making the point that you won't have enough bees to cover all that when it takes almost a month for new bees to hatch out. his right about that and so you need to be careful not to give to much room to quickly BUT we are in the middle of a flow so if you don't expand, you will end up honey bound with not enough room for the queen to lay.
one thing you do want to check and do it now before your top box is filled and heavy: is there honey stored over the tops of the frames in your lower box? if so, your queen may not cross it to lay in your upper box. that's one of the reasons i add boxes under, rather than on top.
if you find that you have honey over the brood in the lower box, an easy fix is to pull a couple of frames up into the top box. put empty frames in the place of those you move.