One more question that I'm sure has been answered in the lengthy change thread, but I cannot bring myself to read 130 pages of it.

Should I, instead of booking the Air Canada coach saver seats now, protect the current saver BF or GF rate by booking it for a date I know we cannot fly (but that has seats available at the saver rate) and then change dates closer to our real date? I know I would have to decide whether to book in BF or GF, gambling on which was more likely to open up when we need it. Then, if nothing opens up, I would at the last minute switch to standard rate coach seats on a non-stop.

Another question, UAInsider seems pretty clear that a date change alone will not trigger a re-ticketing/re-pricing, but what if I choose to switch from the non-stop on the wrong date to an itinerary with a change at EWR, IAH, ORD, or DEN? It's not that I want the layover, but I've noticed over the years that those flights are more likely to open up than the non-stop LHR-SFO. The origin and destination would not change, but would the routing change trigger a re-pricing?