FlyerTalk Evangelist and Ambassador: The British Airways Club
Join Date: Jun 2008
Location: Somewhere between 0 and 13,000 metres high
Programs: AF/KL Life Plat, BA GGL+GfL, ALL Diam, Hilton Diam, Marriott Gold, blablablah, etc
Posts: 33,190
I agrée it’s all going to be about terminals (bcn has sometimes been t3 in the past) and luck and those can’t be assessed so early o. Heck, by the time December comes your layover time may not be 1h50 at all anyway with a timetable change or two!
t5-t5, no major delay, etc you’ll be fine. Terminal change, major snow front in the us etc and it will be dead.
As cws says, on a single ticket, you are protected in terms of issues and so are fine. Two tickets you are playing with fire and have a significant chance of burning yourself.