I'm going on one of Rick's tours to Portugal April 29-May 10. How far in advance do you recommend I book flights? United seems to be the best bet (from Tampa to Lisbon, then Porto to Tampa). It's not cheap, so I'll be going economy. Has anyone out there flown United economy from the U.S. to Europe? I'm 6-1, 175 pounds and a little worried about leg room. Normally I'm pretty good about finding and booking flights, but for some reason Portugal has me nonplussed. Thank you for any kind, patient responses.
There are a couple of options for you to fly and if you can book a Dreamliner, you have bit more space than the 757. Economy is a bit tight and I am only 5'5''. If you can swing it, taking at least Economy Plus will give you a bit more leg room.
Here is the United Site comparing the seat options. I would also check out this link to the 878-10 which seems to be the most prevalent for your trip options: https://www.united.com/en-us/seat-options.
We flew United round trip last year from Denver to Lisbon. Due to our scheduling, we went to Porto and other places before returning to Lisbon for the flight home (long story). I always book an aisle seat, for two reasons. One, I can get up and walk around without disturbing anyone, and two I can stretch out my legs. However, you might just want to pay the extra $$$ and upgrade from economy to economy plus or whatever gives you more room. It's a long flight!
Regarding how far in advance to book, I book at least six months out. You can always change your flight for no additional charge (except for the fare difference), but the closer you get to your departure date the more expensive it will be.
Enjoy Portugal! We had a great time!
p.s., In addition to Rick's Portugal guidebook, I suggest that you spend some quality time on the Facebook page called Portugal Travel and Discovery. Lots of really good travel tips there.