It depends on the opponent - if it was a team mate or someone I had been having a nice friendly conversation with then I would probably wait longer then if it was a tough opponent in a tournament or league where the win is of more benefit then mere rating points.
Although, like people here have been saying, this is correspondence chess where time really should not be an issue at all and for someone to lose a game in such a way is unecessary for anything above 3 days a move.
I only time out for short (e.g. a couple of days) delays when I think I am winning as I then assume the opponent has lost interest etc. Did not take a time out against an opponent who was winning recently and, surprise, surprise, he won. :-(
No regrets though (other than my moves obviously), it is about the games for me and he was an opponent I had played already and was happy to play again.