United has round-trip flights from Dallas (DFW) to London (LHR) for $405-$415 with a connection. October to February. Departures on Tuesday and Wednesday. 7-day minimum stay required. New Years Eve is available if you can stay 10-days or longer.
Note: While this price is pretty good, it’s an inferior deal to the previous ones that were posted, which were nonstop. We do think that it’s a great price if you can do a 10-day stay which covers New Years Eve.