So, that trick FVerbaas described for simulating the socks to keep them from falling off the thighs seems to have worked very nicely. I still have the problem that they tend to fly off the feet (not shown). Not sure about the best way to fix that. Conforming socks work nicely up to mid-shin lengths, so a possible solution could be to simulate the longer socks on top of conforming shorter ones standing in for the feet.

-- I'm not mad at you, just Westphalian.