It depends… Do you know the Fighters? even if you don’t do you like to watch unknown named fighters compete? Do you get bored or burnt out watching marathon shows?
The main Card starts at 5 pm rough ending 8 pm Vancouver time with 6 fights 3 hours scheduled can end early or run late depending on if the fights go the distance
The TV Prelims start at 3 pm Vancouver time 4 fights 2 hours.
Early Prelims 2 fights 1 hour as you mentioned the first fight should be kicking off at 2 pm more likely 2 15 to 2 30 the espn plus days the tv prelims have started with the last early prelim still going on usually
a 12 fight card (unless day of cancelled bouts) usually 6 hours 30 mins per fight this includes fighter walk outs the fight and the decision)
One thing to note this is an ESPN plus card in the states they seem to not be tied to tv commercials and blocking like FS1 and even ESPN has and lots of the cards seem to end before they even schedule to end and FS1 cards almost always went long.
They usually start the next fight right after the one that’s finished instead of waiting for tv talking heads etc.
If doors open at 2 I am not familiar with the Vancouver arena but most arena are slow opening there doors and with security probably wont even make it to your seat until a fight or two is done that’s if you want to be an early bird. Which This is UFC 5th trip to Vancouver in over 9 years so If you want to catch as many fights live as you can. as not many opportunities to do so.
There never is a way to know in the ufc what fights will be exciting and what won’t usually the prelims can be wild people trying to make a name for themselves or they are not even full time in training and so they make mistakes and can lead to exiting early stoppages. That said watching wrestling or BJJ match live in a UFC setting with nose bleed seats can not be the most entertaining or easiest to see the fight.
I would say at latest be in your seat by 4 local time there should be the top two prelims starting then should be a pretty good 8 fights 4 hours from then. Again you could miss some crazy first 4 fights that start around 2 you never know. so your choice.
Make sure your phone is charged something to do in between gaps of fights and probably fuel up and drink lots before you go unless you want to pay concession prices if you get hungry being there a long time at least 3 plus hours, showing up at the latest an hour before main card will also probably mean you miss a huge crowd waiting to get in for the main card and risking missing the first main card fight. if you don’t want to pull in the full card.
TLDR
bottom line up to you what you want 6 hours (12 fights) 4 hours (8 fights) note being an espn plus card if early stoppages they may burn through the prelims fast.so I am rough estimating based on past cards. or main card 3 hours 6 fights