A couple added thoughts about your trip.
If you’re towing a 25’ travel trailer I would most definitely take the Sand Mountain road going in and out. In addition to what’s already been mentioned, there are a couple sections on the Siglerville route that are basically one way traffic, and I don’t think you’d want to back up a 25’ travel trailer for a couple hundred yards if you happen to meet an oncoming vehicle at one of those places. Also, I’m not sure, but the last 1/4 mile of that Siglerville route road along Penns Creek before you get to Poe Paddy might have low hanging branches that could scratch the top of your trailer (Airstream?).
Which ever route you decide to take, drive SLOW. That way you shouldn’t have too many bumps in the road that would pop the rivets on the aluminum skin of an Airstream. Maybe only a couple. 😊 And your overhead cabinets shouldn’t fall off the wall.
The sooner you make a reservation, the better, as the sites at both Poe Paddy and Poe Valley tend to get booked early. Also, since you’re new to those campgrounds, you should pay close attention to what campsite you reserve, as a lot of the campsites at Poe Paddy are not conducive to, or will not hold, a 25’ trailer. And, I don’t think you can see which sites those are from only looking at the campground map. Plus, some of the Poe Paddy sites are right beside the dirt road and they might be okay for a 25’ trailer if you don’t mind all of the road dust from people driving close by throughout the day and night.
As a clarification, isn‘t the winery on the Decker Valley Road rather than the Sand Mountain Road?
I‘d bring your pontoons if you enjoy lake fishing. I’ve stood on the shore at Poe Valley in the spring and watched what I assume were trout rising just beyond casting distance and wished that I had a pontoon or boat to get to them. Just don’t use pontoons on Penns Creek.