I hike mostly in the Sierras. When I know parts of the trail will be sparsely forested (or have no trees at all) taking a Ridgerest as backup insulation is the plan. The hammock ends can be tied to tops of trekking poles to keep the ridgeline high enough to use the hammock as a bug bivy if needed; if not, throw down trash bags for a groundsheet, roll out the ridgerest, set up the tarp with the poles and stakes, and there you are. Lots of people just use the tarp anyway, and you'll have one with you regardless. Of course you want to practice at home first. But Hennessy and similar can be used this way. Some of the heavier, impractical camping hammocks are advertised as dual purpose - hammock or ground tent, like the clunky Lawson.

Then there's the possibility of hanging from rock cracks. At hammock forums there are people talking about climbing gear (cams) but someone mentioned using a rock jammed in the crack as a tie point.

Flexibility is a good thing. I think I'd be able to tolerate a few nights on the ground if I had the hammock the rest of the trip. Call me a fanatic, but not having an ache in my hip is worth the craziness.