Just an update for anyone that's following.
We recently dropped cable tv and are streaming. Two of the three Almonds that are dropping out are ones that feed tvs, they would only drop out while watching tv. The third Almond had no issues. I pulled the Almonds and put in another router and, so far, no drops with the same usage pattern.
This sounds like a classic overload situation, Almonds aren't broken, they work after cooling down. The longer I let them cool, the longer they last. I'm going to hardwire the rest of the tvs but I think I'll leave the Almonds doing lighter duty in AP mode.