Jackets/coats for big butts

I’ll be traveling in late January and I’ve yet to find a coat/jacket that is warm, waterproof and able to fit on women with wide hips, thick thighs, big butts without fitting super loose on top per reviews of women with my body type. I tried on my bf’s patagonia parka and my hips were tight and when i sat it bunched up in my waist because there was no room around my hips/butts. Any recommendations on clothing brands I can look into? I know what specs I need (waterproof, warm, etc) I’m stuck on what brands I need to look into and models exactly. Should I just do a bunch of layers and top it off with a waterproof windbreaker and call it a day? I don’t have many options where I live so I’d be ordering online. I’m used to tropical climates so I want something really warm that I can do some light hiking and waterfall visits. Oh and glacier visit and aurora borealis hunting. I’d love a bright red one but that’s not super important. Any help is appreciated.