Upvote:2
Is my assumption that I need to be at YVR at 4:05 correct?
Yes, it is always recommended to arrive 2 hours before your flight.
Am I correct in saying that the above two options are basically the only ones? (Except that I can take Canada Line earlier than 1:06 am and that I can take N10 earlier than 3:09 am.)
Yes, that is correct. In my opinion, the bus should be fine. Worst case scenario you can get a taxi. There are some hotels that offer 24-hour shuttles though.
I assume it makes no sense to arrive at YVR earlier (say at 11 pm on the previous day), is that right? People aren't usually allowed to spend night on the airside, but the landside should be ok, right?
You're right. It doesn't make sense to arrive that early. Vancouver airport, the Internaitonal airport is open 24 hours and you can sleep there. There is a sleeping guide here.