In my experience, Hartford's Bradley International Airport is one of the easiest airports to navigate, well compared to Philadelphia International Airport. There's abundant parking options, but my most favorite parking lot is the Z Airport Parking at whenever am in Hartford's Bradley also known as BDL Airport.
Z BDL Airport parking offers the most convenient parking for Bradley International Airport, you can ask somebody who is from Connecticut and for sure they know that Z is known as "the stree-free" Bradley Airport parking option. My other reason is it puts me that much closer to home, since I stay in the Farmington Valley whenever I am in town.
No need to look further anymore cause Z has much cheaper rates compared to other paking lots there in Bradley and whether you need parking for a day or need long term parking at Bradley Z it is!