Here is one idea that is 12 hours from south-central PA. Not sure exactly where in PA you are.
CLICKThis on the Baskatong Reservoir in Quebec. We go there almost every summer and you can rent boats there as well. Don't expect much from the campground but the main purpose to go there is fishing which is good on the large lake if you are willing to travel a bit to the more remote areas on the reservoir.
If you really want good walleye fishing, though, you can get daily or longer fly-out trips from several outfitters who will pick you up there. Not cheap, but its the best way to get into the really good fishing as well as a lot more of a wilderness feel.
The best time to go for walleye is June....as far as the bugs...well, you never know, esp with the skeeters...they can be bad or totally absent anytime of year but it depends on how wet it is where you are. Just get a good bug shirt.....chances are most of the time you won't need it (esp out on the water) but they are worth their weight in gold when you do...