If you include the drive my husband already does 11 to 13 hour days five days a week so three days of 14 to 17 hours would be an improvement ... I guess. Or I'd be a widow. At least he'd get caught up on his sleep and we'd actually have time to do something over the weekend regularly.
Frankly, I've always thought the whole five day on/two off is bullshit and unncessary. Just a way to keep people so busy and exhausted they have no time to think.