Lol you could get a huge ass rubbermaid and rig up some sort of "dividers" inside it to give you about 20 spaces...actually... doing that and stacking one on top of the other could even turn it into a nice little 20 plant SIP where the dividers guide the roots down to the Res instead of letting them fight and tangle.... so it could work for soil still.... or even all perlite for a "hempy" type grow...
ehhh.. be creative.