Well, you wouldn't be traveling 470 miles in the span of 7 hours to begin with. Not only because of posted speed limits, but also because of traffic, and the stop-and-go nature of driving through more heavily populated built-up areas. If you wanted to drive 470 miles across Montana and you wanted to arrive at your destination within the span of 7 hours, it would likely be possible, but you're not going to be doing 60 through D.C. and the surrounding area, no chance. Personally, unless I had a really good reason for doing it, I wouldn't want to cover the better part of 1,000 miles in the span of a single day. If it's worth it to make the trip, then so be it, make the trip. But a solid 8 hours of driving is enough for a single day unless there's a pressing need to tack on a greater number than that. Book a room in a roadside motor lodge, cheap motel, find a bed and breakfast or reserve an Airbnb. If you're obligated to be somewhere immediately after you're through presenting, then why not have someone come along for the ride? You drive there, they drive back, or vice versa, or alternate, it doesn't matter. But spending 16 hours in the car to wind up right back where you started is something you ought to try and avoid.