And there was a chance Rivian went under before delivering anything. At least Rivian had Amazon vans to sell. So as of today there are no EREV vehicles for sale in the US.
Have you had it checked? I live in Colorado and much colder than Oregon. I park my truck outside all winter and still only see 1%-2% a day even when it's near 0F out. 4-7% sounds like something isn't turning off like having a seat belt buckled.
good question. Not sure the average person even knows about shipping mode and it's buried in the menus. A "button" for leaving for a long period of time would be nice to have. And when I used shipping mode when my truck sat for a week it wasn't noticeably different than just leaving it locked.