Per Wikipedia:
Williamsport Regional Airport's (IPT) Runway 9/27 is 6,825 feet long (it's the longer of two runways at IPT, at an elevation of 528 feet.
A Boeing 757-200 requires 6,800 feet for takeoff. No, that doesn't mean IPT's runway 9/27 is long enough. In a dire emergency, yeah, maybe. For routine operations, no way.
A 737-500 Basic configuration, per Boeing, requires 5,880 feet - that leave about a 1,000 foot margin, so this bird could probably operate out of IPT. This plane can carry about 110 people. However, a 737-500 has a range of only about 1,400 miles, so wouldn't work for club's needing longer ranger (that's not coast-to-coast mileage!). So a club could charter one for a flight to Williamsport, as long as that club was coming from somewhere east of the Mississippi... but that's not a standard MLB charter.