I was thinking about this on the way to work, and like you said earlier maybe it's better to do Sunday to let the trails dry out. Weather report is looking pretty iffy.
The wife/life card is for a 3+ hour ride. I don't think you're in the realm of "hobbyist" if the requirement is 4.5 hours of riding.
It funny because the reason I'm mostly iffy on this is because I wanted to do a group ride this week and the idea of moving the ride if nobody verbals and so on doesn't really qualify, so I debated posting a set MTBNJ group ride aside from this.
If you want to make this the Weekly MTBNJ Group ride do it, set a time and a day and don't pull the moving start time stuff. Just set it and go with it.