I don't get any heat on the floor of my Avalon either I had it in at Toyota dealership I spent almost $1000 and it still doesn't work, they replaced everything down to antifreeze because it wasn't red. I would really like help with this (besides getting new boots) like the toyota dealer told me in the end
If this was the initial problem for spending the $1000, you should get the dealer to have it rectified under warranty as they did not fix your initial problem and you should not be keeping quiet about it.
If you have heat at all other positions, the problem should be with the air outlet servomotor. Either it is not moving correctly or some adjustments are out of specs.