Any solution to the problem above will also be a solution the general problem of arranging 20 golfers in 6 rounds of foursomes, and the latter is known to have no solution. Look for "20 golfers play in foursomes" on
Ed Pegg's social golf page. Larger tournaments are possible. The next is 32 players in 10 rounds of foursomes (a spouse avoiding version of this is given on the same page), after that the next would be 44 players in 14 rounds of foursomes.
I am not sure if you appreciate that the format of play here will be different from spouse avoiding doubles, since some of the foursomes might be all male, others all female, and the remainder somewhere in between.