I have been on Continental/United flights that had much more then 20-30 people, & the crew was extremely gracious in assisting with 2 minyanim, it was done respectfully and with ZERO disturbance to any passenger.
I have been on ELAL flights where a minyan would cause no disturbance as it was in middle of the night and most passengers were sleeping, but they wouldnt even consider any attempt to help a minyan….
Oh and I love DaMoshe’s comment, that ELAL knows of this psak & therefore prevents minyanim, well this is probably one of the only psakim they hold of….. maybe we can get all those rabbonim to pasken that its prohibited to be Mechallel Shabbos, so that ELAL should adhere to Shmiras Shabbos…now dont start tellig me that ELAL is Shomer Shabbos, go online and search for flights on any shabbos day & you will find ELAL flights that are mechalel Shabbos…