I've done parasitic draw tests. The draw drops to around 15 mA after 10-15 minutes. The highest I've seen while it's sleeping is about 35-40 mA. I know about the problem with the sat radio, but have been told that if I have Sat 1 and Sat 2 as sources it's already been upgraded.
I'm convinced that something is drawing it down over night, and that in cold weather, several nights is all it can handle, but I'm at a loss as to how to catch the gremlin in the act.
The car was first titled in 2/11. Carfax shows an electrical system check that month, and again in 11/13. When I got the car in 2015 it did not have the original battery. It had the oversize battery, a Duracell/Deka. IIRC, the battery date code showed it was new some time in 2014. I almost replaced it in 2016, but ended up nursing it for another year. I replaced it in 9/17 after charging and testing it on a very fancy, FAA approved battery tester. It tested at roughly 70 minutes reserve capacity at that time. The replacement was an Exide Extreme, also L5/group 49. I exchanged that battery in 10/18. It is possible the first Exide was just partially discharged and didn't need to be replaced; I based my assumption it was fully charged when I tested it on the readings I was getting from the volt meter in the aux socket.
One thing that may be related: the seat memory doesn't work, as far as I can tell. The buttons won't store anything and the seat rarely if ever moves when you unlock the door with either fob. (The fobs used to work, sporadically, but no more.) The passenger's side mirror does seem to have a mind of it's own, though, as I often have to adjust it when I get into the car.
Someone pointed me to the siren. Is there a fuse I can pull for that? It looks like a PITA to get at the actual siren. (Could this be the problem, given it drops to 15 mA after shutdown?)
I have left the battery disconnected for a few days and it seems not to discharge then (I'm not surprised!) but that's not a long term solution as I can't be going out to reconnect it every morning, and I hate having to reset the clock...

BTW, how long should I be able to play the radio without running the engine? I had a Yukon and we could get through the first feature at the drive-in easily. With this car I doubt I'd get half an hour. Makes me think the battery isn't getting charged properly, but it's the same wires that power the starter, as far as I can tell. (I've measured the charging voltage at the battery terminals and it's over 14 volts.)
TIA,