I'm late on this one, but within the 3ish hour range you have a ton of stuff you can see. I've been trying to explore more in this range this summer. I'm targeting spots that you have to at least walk in to fish, and preferably hike to get there. That way if I get skunked, at least I got a good walk in.
With this range, you can get to all the of the Shenandoah streams near the Swift Run Gap entrance. I'm not sure if they've got much rain the past couple weeks, but I think they are still pretty low at this time. I did Big Run, camping overnight, about a month ago. The Shenandoahs are open for backcountry camping, but I'd check the regs before heading to any particular spot. I can't remember how restrictive they are. Once you get away from the north end of the park, it gets much less congested. If you're accessing these streams from the park, it'll be a hike down and a hike back up to get out. You'll see some reviews of the Big Fork that talk about how terrible the hike is, but I didn't find it any harder than any other ridge climb that I've done in the Shenandoahs. Yes, it sucks, but it is only around 2K elevation gained.
Two weekends ago I did a trip to Laurel Fork/Upper Jackson River/ St. Mary's River. The Laurel and St. Mary's were unfishably low. The Jackson was fine, and I camped at the campground, which was $5 for America the Beautiful pass holders, and $10 without. You can't camp by the Jackson outside of the campground as far as I could tell. For the Laurel Fork, i'd plan on camping at the parking area at Locust Point area and hiking in and out. About 6 miles round trip, but not terribly challenging hiking. Well, I'd bet it would be a better hike if you weren't carrying everything for an overnight :/
Hope this helps. I know I'm always interested in hearing more options in this range. I'll likely do another over Labor Day weekend, but I'm not sure where.