Cool Temp Companions For Paradise Fish??????

My child has a 20 gallon tank with 4 paradise fish (Macropodus opercularis).  I
think they're all female fish.  My reason for choosing these fish is because we
have had frequent power outages in our area and I wanted fish that could easily
withstand 65 degree F. water if necessary.  Any suggestions on other fish that
could both be accommodated in 65 degree temperatures and reasonably get along
with the Paradise fish?  I thought perhaps some female betas would work.  Any
suggestions are appreciated.