Fellas, with my tun I've done a "ton" of overnight mashes, all of which have gone very well. In my cooler/tun I lost about 10-12 degrees overnight = no concerns.
In my second ever BIAB, I'm thinking about doing it tomorrow. Tell me if this sounds okay.
At lunch I go home and fire up all my water in my converted keg/kettle, and mash in BIAB. I'll wrap the keg with a couple moving blankets and cover the top with the same. Between noon and 530'ish I'd expect to lose at least 10-12 degrees, possibly even more since we're talking far less insulation than my cooler. Regardless... conversion will have occurred. I don't think there's a worry about spoilage either in this whole timeframe. Gonna give it a try.
Any holes in my plan to poke?