Originally Posted by
mmack
Right now, it seems that I can't book a SFO-YVR-ORD-LHR ticket without the fare becoming MUCH more expensive. So I am planning the RT SFO-YVR on a separate itinerary. Maybe we will do carry on only.
With SFO in the mix, there is always the risk of flight delays and missed connections. If you have separate itineraries you're not protected onto later flights. All of that is a long way of saying I'd go with your plan of arriving the night before.