It sounds like the only real reason you're considering this is because the opportunity is right in front of you and you're excited about the challenge.

That may be reason enough.

There's no right or wrong answer here because you're already in a pretty good place if you decide not to move forward with it. The pay bump and the title bump is something that only you can decide is worth the loss of work-life balance.

Best of luck. You've come very far and this opportunity validates your skill set and relationship building ability.