Thoughts on sleep sack for 13m?

Hey everyone! My son is now 13m and he’s been walking since 10m (he’s almost running now it’s crazy!). He’s FINALLY sleeping thru the night @ 12+ hours and I couldn’t be more happy with how he is developing and growing! I don’t think I need to change anything at all, but I got bored and thought about how he still uses his sleep sack. I don’t think he needs it anymore but I’m also in no rush to ditch it…and we haven’t tried a sleep or nap without it, but I figured I’d reach out to the community and see what everyone else is doing/has done around this stage 🤷‍♀️. The sack is a halo zippered size L. Plenty of room for his feet to move (he can walk around his crib in it and it’s like a penguin so cute haha), and arms are free of course. Occasionally I’ll give him one of his old receiving blankets in his crib and he has a lovey in his crib too. I know he’s safe with these items because he plays peekaboo with the items and knows how to take them off his face. But yeah, any thought on continuing to use the sack? I think the only reason we still use it is because I don’t want him to get cold! He also has not attempted to climb out of his crib and I’m thinking it’s because he can’t get a grip on the crib with his feet because of the sack? This is pretty much an irreverent post but I was bored and curious about what other moms do since I have no mom friends irl 😆