We took that trip last summer in the model S. Nice drive with plenty to see. If I recall the Springfield to Grants Pass includes a bit of elevation and I kept getting the warning about haveing less than 10% energy at your destination. If it is your first Supercharger trip stay plugged in a few extra min. at Springfield to avoid that warning. At no time was I worried about running out of juice but the message can be nerve racking to passengers.
I recommend the California coast for the drive (it is far prettier than simply going down I-5. If you leave I-5 at Grants Pass after charging there, you can get to the coast at Crescent City via hwy 199 and come down hwy 101. The next supercharger is the newly opened Ukiah charger, so you will have to make due with level 2 chargers along the way since Crescent City and Eureka superchargers are not yet ready, but the scenery is beautiful (and we would be happy to see you for some charging at our house in Big Lagoon). Prairie Creek state park (Newton P. Drury scenic parkway) which parallels hwy 101 for 10 miles south of Klamath is not to be missed. Lots of winery interest along hwy 101 as you get further south into Mendocino and Sonoma counties as well.
Typically speed limit plus 1-5. Not overly aggressive. But I was amazed how on the flats the additional weight seemed to make very little difference. - - - Updated - - - We were planning on coming back that way but the storm came with wind and rain (I've done it many times on motorcycle.) I have the Chademo adaptor, but California doesn't seem to have any/many as opposed to Oregon. Can't wait until they start putting superchargers on some of the more popular scenic routes.
I've had the exact same experience on both sides. One stream of water from right in the middle of the FW. Lands on the edge of the seat or just inside depending upon the tilt of the car.
So how does the front side passenger seat feel on a very long road trip? When taking the Model S for a 350 mile trip, we end up annoyed by the hard headrest towards the last 1/3 of the trip. I don't notice it as much on the driver seat since I am more engaged and leaning a bit forward, but when leaning back on the passenger front seat, the hard surface and bumping from street roughness can cause me a headache, even on a recent 2015 P90DL. Has this been improved on the model X?
My passengers love the seat. One friend on our trip commented that she normally gets sciatica riding long distances in a car, but no hint of it in the X. I finally let my wife drive for a one day trip we took last week, so I got to try it out first hand. Best seat (drivers and passenger) I've experienced in a car.