Do I want the XS or S in the Cozyfleece Mega Sweatpants?

I'm 5"3 and 115 lbs. I wear an XS in most other brands and have 24-25 waist depending on the brand/fit. It seems like Aritzia runs small because I wear S in the Perfect Crew Sweatshirt (oversized) and the HomeStretch Longsleeve Crew. I'd like them to fit loose, but not so loose that I have mega diaper butt. I've also heard they shrink the wash.

Also, are the ankles noticeably smaller in smaller sizes? I can't stand when the ankles are too loose and cause the legs to slide up.

I haven't shopped with Aritzia much yet and it seems like they've changed the sizing of these anyway, so I don't trust reviews! Any help would be appreciated! Thank you!

Hi!! I know TNA is now Aritzia but the sweatpants don’t fit anything like the old ones. I ordered the “sweat fleece cozy fleece mega sweatpant” so that I could have another pair of my all time favorite “cozy fleece mega sweatpant” and they’re so tight despite being the same size, like genuinely not even the same fit. Am I missing something here? I lift so I have pretty muscular legs and it’s really hard to find sweatpants that have a genuinely baggy fit on me like the TNAs:( I’m devastatedddd. I thought the rebrand was literally just slapping a different name on it lol