Summer time ride? Forget it, between the air cooled engine and all the super fine dust (St Helen's ash, silt, alkakli flats, etc), the side winds, the lack of fuel stops (unless you really like the diesel and urine stench of truck stops)... I used to make runs all over eastern WA, hauled primarily heavy exports loads to Seattle and Tacoma (was based in Fife).
I'd recommend having a bike with a radiator or at least an oil to air cooler for a run like that. And a much better seat, bars that are not a compromise, windscreen if not an outright windshield...
The longest I've done on a Savage (with a decent seat at that) is right around 500 miles in a day. Anymore than 120 miles and I'm taking a full grown bike (I'm way too big at 6'2" 235 for a Savage). Even if mine didn't get a whopping 36 mpg and have a 2 gallon tank...