yes.
5 universes can be done with (2) EtDs... or (1)EtD and (1) USB pixelnet dongle.
from your question, I assume that you are using more than 16,384 channels. that is why you'd need 5 (or more universes)
just another thought:
if you can mirror channels -- have a row of candy canes that play an identical pattern of lights, you could have each of the candy canes share the same channel assignment...
ie. each cane might have 50 pixels (and 150) channels. if you had 50 canes, then you'd have 50x150 channels= 5250 channels. BUT if you had each candy cane use the same pattern of lights, you could make due with 150 channels -- listened to by each SSC (or falcon string).