What's the best way to snag a RT in LH F, if you're going for longer than a week or so? Even if you book the outbound in F, it'll be tough to get any availability on the return before travel begins (correct me if I'm wrong, but if UA is like US, you can't make changes after start of travel). Is booking the trip as separate OW tickets the best way to accomplish this, or is there another program/trick here?