I still get this feeling that LE knows it’s that area they have been focusing on. The one where apparently TS made the detour than had to turn around. I think they’ve stalled the search because of the snow, and waiting for the thaw.Those methods are seldom used when someone has a great deal of time to work with, and she didn’t have that luxury.
There is no evidence she plotted this for any significant length of time, and the abuse charges seem to preclude any extended planning.
I believe she planned to kill him, but it was still a reaction to an unplanned event (abuse that went too far).
Gannon not being found is easily explained by the large area in which she could have dumped his body.