Fridge is ok yeah just put some dry rice if any mold gets to one seed they will all be fucked in a few days. For potting yes you can put two plants in a 3 gal bucket and grow them but its not a very good idea marijauna plants like all of everything they can get it will just slow the growth of both sometimes one plant will become stonger than the other and the bigger one can somtimes snuff out the smaller one.