In April of 2005, I toured the route. The Truckee MOW building had at least one modern 'snow-cat'; a steel-tracked cab-over vehicle that looked like it would hold four to six people. Barring that, I can't imagine what significant technological advances over the past 50+ years that could overcome a train, bus or anything else as large- that is snowbound in some mostly-remote location. People still die in Yosemite National Park on a regular basis, just as people still drive around crossing gates with clear results.

Ultimately, a rescue that would be viewed as 'more sucessful' than that of '52 would probably derive its root energy from competant, thoughtful and extremely energetic PEOPLE. Figuring that the largest obstacle in retrieving a snow-bound ANYTHING is tons of frozen condensation, I imagine that the best tools are that which have already been proven. As far as technological advancements since 1952, Napalm may be a consideration...