An update:
First, I want to thank Todd to connect me to Ford service people. I left my car at the dealer and they provided a free rental car. This was a week ago.
Today, I came back from the dealer and they did not find anything wrong with my car. The parasitic draw is only 20 mA, which is below 50mA limit. I suspect that the battery drain must have been triggered by something, maybe open the door with keypad or trunk. But it is so hard to reproduce the problem without knowing what causes it. I will keep an eye on the car to see under what conditions the battery dies again.