I have the same problem. After having my battery die after not driving for several days, twice, I bought a new battery. The battery guy said my current one tested out fine, but I figured after about 5 years it was worth putting in a new one.
Now, during COVID shelter in place, I have had my battery die three times (this is the new battery I bought about 6 months ago). After the first time I've made a point of starting the car and letting it run for a while. The first time it may have sat for 2 weeks. The next time was about a week. The most recent time was 6 days.
I have one theory: my car has the "welcome lights" when the key fob is close enough. Sometimes I leave my keys right by the door which is within 10 feet of the car in the driveway. I don't see the lights come on in the car, but I wonder if the keyfob is close enough that it communicates with the car to see if it is approaching or staying still.
I had been keeping the key fob at the other end of the house. It seemed to help. When it died this time after only 6 days, I noticed the key fob was at the front door.
I'm going to keep experimenting, and hopefully remembering to leave it at the other end of the house.
For the record none of my lights are accidentally left on or anything like that. I used to subscribe to Infiniti Connect but that stopped working a few years ago. Maybe that's a problem that it keeps trying to connect.
But this is really annoying. I feel like I might come to a dead car in the airport parking when I'm on a long business trip, when we can do that again. It never has happened, which might support my theory that the keyfob is too close and constantly communicating with the car, even if only to tell it "I'm close but I'm not approaching you so don't turn the lights on this time".
Has anyone else associated it with the "Welcome light"?