I don't even know that there's such thing as bodystocking. I've always thought that it's more or less the same thing as bodysuits.
To my local understanding, bodysuits are made out of some "non-normal" material, like rubber, while a bodystocking is made from fabric. Apparently in current Danbooru tag parlance it looks like bodystocking should implicate bodysuit.
It's not a bodysuit or the like. She's just wearing a stretchy top and bottom. It's referring to UNIQLO's Heattech undershirt and pants.
oh dear...People from Tōhoku don't feel the cold at all!heh!Don't undress, don't undress!Welcome home, mistress. It's cold outside, isn't it?...take a look!Full body heat-tech innerwear ♪I didn't think it could snow this much in Tokyo...On a certain day, in February...Wah ha ha!I'm perfectly fine with it ♪You perv!It's unbearably cold ...Really...