"it's probably impossible to commute for a good while after joining",....
completely possible and done by many.
Alot of the comments re seniority here, though true, are being made by senior guys who....have done their time....but are a bit out of tune when it comes to being at the bottom of the 400 list. You would be surprised where a intuative FO can get and still enjoy some parts of the weekend off.
Concentrate on getting the offer....