Brand New Point Zero Puffer Coat - flexible material - covers half of bum

I wore this beauty two times, and sadly it's too small. Plus for me, I need it to cover my WHOLE bum because I live in Chicago and I have a sensitive bum. It's rated to -18C (which is -0F), which is pretty effing cold, especially considering this jacket is super light and flexible (aka you can sit down in it). I personally just need a longer one because my old one (that has actual rips in it I love it so much) is long and now I'm ruined forever for shorter jackets. Apparently,. Would have been nice to know before I bought it in Canada, and now I can't go back there to return it until the return window has closed. Anyway. First world problems, but still. I don't have space in my one bedroom condo for coats I don't wear. Best offer and it's yours beauties! Oh and also I'm 5'3, the first pic is of me wearing it and showing that the pic in the store the day I bought it was Oct 29th so yeah like two weeks ago. I'm 5'3 and 125lbs.