So mommies who have chunky babies, what kind of socks do you put on them? I buy my son 12-18 month…

So mommies who have chunky babies, what kind of socks do you put on them? I buy my son 12-18 month socks and they are so tight on his little legs. The foot part fits a bit big but the elastic cuts into his poor legs. It's still kinda cold here in Wisconsin so I put socks on him. Also how do you keep baby socks from shrinking?