in the general forums, my wife and I have been playing quite a bit starting with three rounds of Tides of Time and then continuing through three rounds of Tides Of Madness with the keepers from the first two rounds of Tides Off Time still in play.
Generally our play styles are defense based, and so we wind up with tighter games than when we play one game or the other alone. The occasional blowout feels so good now because it is harder for us to pull off in a six round game.
To fit everything in one box we laminated four pairs of score sheets and replaced the madness counters with smaller (but heavier) Lovecraft coins then replaced the pencils with dry erase markers. I am using four spare poker chips from Lovecraft Letter to mark the Tides Of Madness keepers.
I am using the Tides Of Madness box with the Tides Of Time lid.