I took my bettas from alaska to NY in January. Only 2 made it but that was because of a rather freak accident and had nothing to do with moving them (the backseat window was open, it was -40F outside and my fish were under the window
). Since bettas breathe air, I didn't have to worry about oxygen since they werent in bags.
I would think they would be OK for 14 hours. AB sellers ship fish all over the country and petshops get fish mailed to them. Right? Even if they go express thats still about 24 hours in a bag