With a decently geared level 80 tank...
You can boost a team from 1st to 60th (with RAF) in 2-3 days of real time.

I would think, with a half geared 80th tank.
60-70, boosting would still be fairly fast.
But if you having flying mounts and heirloom pieces, questing is a decent pace.

Anything prior to 71-80, only requires 70% of the experience it used to.
They've lowered the amount of exp needed per level by 30%.
Add to that, up to a 19% boost to experience from two heirloom items, and you're basically looking at half time, compared to when it was current content.

1st to 60th, without boosting...
But with RAF on a team.
I'd probably quest all the way.
Take kill quests, but skip on collections.
Not really sure on a timeframe for a first team, but you'll level fairly fast.

You have 3 months with RAF, so should be easily enough time to get a lot of teams leveled some.