> These quickly get in trouble and either die by bears, by drowning, by freezing or they are rescued by park rangers or other rescue personnel–but often, not before risking their lives and/or spending a lot of government money on helicopters and overtime
Since 1992, only two people have died trying to reach the bus, they both drowned in the Tek (which was hard for me to cross, at 6 foot 2 and 185 lbs). One in 2010, and one last year.
As for the number of rescues:
"The state carried out 15 bus-related search and rescue operations between 2009 and 2017, authorities say" [1]
[1] https://www.bbc.com/news/world-us-canada-53106441
For what it's worth, I lived in the Yukon for 4 years. I've been bison hunting at -45C, I've spent months hunting, hiking and fishing all over the Yukon and a ton of time in Alaska too. I know what it takes.