HS=Hot Springs ... DOH!
If he's heading to the hot springs (ski3pins second home ...

), then I suggest heading east out I-84 to Ontairo, OR, then south on US95 just inside Idaho to Winnemucca, Nevada.
At Winnemucca, there are two options, both somewhat roundabout. Route 1: I-80 east to Battle Mountain, south on Nevada 305 to Austin, Nevada 376 south to Tonopah, west on US6 to Benton.
Route 2: At Winnemucca, southwest on I-80 to west of Lovelock, south on US95 through Fallon and Hawthorne, southwest on Nevada 360 to US6, southwest on US6 the last few miles to Benton, west ib California 120 the last couple of miles to Benton Hot Springs.
If coming south on US395, be aware that California 120 between just south of Lee Vining and Benton is closed for the winter. That necessitates going south all the way to Bishop then north to Benton. There is a county road that cuts off just south of Mammoth Lakes, but is subject to snow the entire distance and is a lesser priority road for snow plowing.