Hello!
I'll be landing in Narita on 20th November 2017, and i plan to go to Sapporo on the same day. I have bought JR Pass and are going to exchange it the moment i land. I'll be going to Sapporo by Vanilla Air, though i haven't booked the ticket. My main concern is, how long will it take to exchange JR Pass in Narita? 2 Years ago, i spend 3 hours or more in queue to exchange JR Pass (lots of people, maybe because it's sakura season). I need to know how long will i spend queueing to exchange JR Pass for me to be able to plan what time will my flight be. Anyone can help? Really appreciate it.
As you found out before....Depends how many people are in line.You might be lucky,or not....
BTW why are you getting your pass on arrival and then flying to Sapporo?
My flight will land at 07.00 AM, so maybe not too much...i hope....
My first plan was to spend 3 days in Tokyo then go to Hokkaido, but then Comic Con happen and i had to rearrange my plan. So i decided to go to Sapporo first. At first i'm gonna use Shinkansen, but it took about 8 hours, and it will be night by the time i arrive in Sapporo. And i'm only spending 2 nights in Sapporo, so i have very limited time to explore if i arrive late on the first day. So other option is by plane. I'll be using Shinkansen from Hakodate to Tokyo. Confused? Yeah, me too...if not for Comic Con *sigh

You can exchange your JR Railpass at New-Chitose Airport Station too and at Sapporo station according to this website : http://www.japanrailpass.net/en/exchange.html
If the queue is too long at Narita Airport then you can exchange in Sapporo or at the airport.
Oh wow. I totally forgot that i can exchange it outside Narita XD ...seriously. Anyhow, thank you for replying to this dumb question and opening my mind... @lucapal and @wateenmooiedag

Why would you waste your JR pass by activating it when you know you won't be using it?