I'd think, if you have the option of a legitimate dungeon finder team.
Five toons, one who can tank and one who can spec to be a healer, even if you don't run them that way... as long as you have enough heals and a tank...
You take those five and use Dungeons to level to 90th.
Even if you do trash and then reset and use dungeon finder to avoid the limits on instances per hour.

Once you have a 90th booster...
You can park the alts somewhere and boost... such as Deepholm.

You could also borrow your tank and/or healer...
And level additional toons through instances.

Plus you could park your level 90 team nearby.
And quest or boost other toons.
If you're camped, log on the level 90 team and see how they like that.