Phone and UHF Repeater Coverage Snowies Western Wilderness

[Stew63]

Am planning on a trip up Hannel's Spur and the general Western Wildeness Area of the Snowy Mountains. As much as I don't like to involve myself in technology when out enjoying nature I thought it might be best on this particular walk to have a back up mobile and/or UHF.

1/. What's the mobile phone coverage like (ie. where does coverage roughly 'kick in') on climbing Hannel's Spur and the general western slopes above the lower valleys?
2/. I understand there is a UHF repeater at Biggara (Mount Youngal?) is this actually/still correct?

Thanks...