I totally get this issue. If I ever get a new job it will likely mean giving up a train commute, which is long but not totally horrible, for a car commute, in NJ traffic.
I also understand the 15 minutes of playtime at daycare. I have a 3yo and it breaks my heart to leave him with other people in the morning. My wife gets to pickup, she is the hero! Although he likes daycare, you wouldn't know it at 7AM.
51 cents per mile sounds like a high cost of commute. I think that's the federal expense rate for miles reimbursement? Its not a hard and fast number. Its got to account for average wear and tear on the car, tires, maintenance, and fuel - all of which are highly dependent on the vehicle, the trip, and the driver. Your costs may vary.
How LONG will the commute take? If its 30 more miles at highway speeds, that's around an hour a day, and significant but not unheard of. If its 30 miles on backroads, or in reliable traffic, that's a consideration.
Finally - depending on where you are there may be programs that will help you get into a carpool, or map a transit route, etc... in New Jersey and I think most of PA they are called TMAs, Transportation Management Associations. The one in Metro New York is called Metropool. There may be people at the new office taking the same commute that you can ride with, and a TMA can help match you with them, although I know the daycare trip can sometimes interrupt that sort of thing.
Good luck getting an offer and making a decision!
theSchmett