alternatives for odd # of players in hand and foot canasta
I have a few ideas off the top of my head.

First, one thing we have done in the past is to have one of the "more experienced" players play multiple hands.  It is a little complicated because that person has to pull double duty.

If you go this route, you may also want to try and not have the person play their two hands right after each other.  This way there is no issues with the person discarding something from hand 1 that hand 2 desperately needs.

I have been the 2 handed person a few times, and the extra effort sometimes makes it seem like I am paying more attention to the game and not in having fun with the people around me.

Another option would be to have somebody sit out each hand.  Maybe two people can share one "seat".  This gives somebody (like the host) to get up and check on everyone and all of that kind of stuff.

Last, invite somebody new to the group.  The more the merrier!