There are such things as dual residency for tax purposes such as an agreement Pennsylvania has with Maryland but for registering and insuring vehicles I know of no dual insurance available in the U.S. If you are working and spending 80 percent of your time in Philadelphia it sounds like you are likely a resident of PA and not Florida now.
If you are a resident of Pennsylvania, you should get your driver's license there and register and insure your vehicles in PA as well. You can double check the residency laws with the Penn. Department of Transportation. You would be covered when you travel to Florida in your vehicle. You may want to have limits that are higher than normal in your resident state IF you travel to states that require higher limits.
Start now getting your Pennsylvania online auto insurance quote.