Jeff, nice review. On the subject of all-season tires in icy, cottage country conditions: For what it's worth, last February, during the iciest, snowiest part of this past winter, we drove my girlfriend's 2010 Wrangler with fairly bald all-season tires from Montreal up to Lachute (Quebec cottage country), including up some seriously steep and icy driveways.
I was blown away by how capable the Jeep was with bad tires. Of course, thankfully we didn't have to make any emergency stops to further test the traction of the inappropriate tires, and we drove very carefully the rest of the time, but as far as getting up a long, steep, icy hill, the thing was a revelation. I realize there may be a big difference between a Jeep's dedicated low-range 4wd and a Range Rover, but it goes to show, depending on how allegedly competent the RR's off road bits are, you may have fared just fine.