An emergency rappel with paracord is asking for serious injury or death. It's too narrow and slippery to work right for rappelling. Paracord is rated for 550 lbs of static load; the dynamic loads of a rappel would be between twice and four times your body weight. It's also too stretchy under load.

A lousy but possibly better option would be to tie a foothold-sized loop every couple of feet and climb down. You'd have to tie big loops to fit your skiboots in them, and you'd have to be 100% confident in your ability to correctly tie yourself off. Dynamic loads would be less, and if you had enough length to double it up it might work for one person, once. That person could then ski down and get help for anyone left behind on the chair.

Paracord is useful for a lot of things but for this scenario I'd much rather carry a PLB.