There are no good solutions once you are down to 6 teams.It's a blind draw, it's not going to be a perfect every time. This is just a tournament with six teams...nothing more.
You can have group A play group B. This risks undefeated teams getting knocked out. Not satisfying.
Or you can have two round robins, each with 3 teams. For someone, their second game of the day is the other team’s first game. Not fair.
Or, you can play a 6 team round robin. This takes a long time. And no final. Not satisfying.
Or you can do a single elimination tournament, where two teams have a bye. Again, not fair. And it’s a long drive for just one game.