Initially I planned to write an article on how to nest two round trip tickets for a winter trip and a summer trip to London at a discount ticket price compared to summer ticket prices. Turns out that strategy is not necessary today since United Airlines has ticket prices as low as $488 round trip for travel in July 2020 for Basic Economy.
Be sure to watch out out for the booking codes. Several dates I checked were all United-operated flights booked as Lufthansa codeshares. This could be a big difference in frequent flyer miles earned.
United Airlines San Francisco SFO – London LHR – San Francisco SFO