Same thing in Wisconsin, depending on where you live, you can't buy liquor after 9pm anywhere but in a bar. However, uou can pay for a six pack or whatever at a bar, have it put in a sack and go home. Which means you are overpaying for the six pack but to each their own. Some tavern association has lobbied for years for this b/c they don't want your booze money going anywhere but in their pockets, at least after 9pm. And things get tricky because according to Wisconsin law, there is some leeway and some communities can sell beer until as late as midnight at convenience stores. The Town of Madison, for example, keeps selling until 10 p.m., while the City of Madison sells until 9 p.m.
That's because the Wisconsin liquor laws also provide for Class A beer license, which means a store can sell beer or any malt beverage until midnight. The community sets the specific cut-off time, which in Milwaukee is 9 p.m. to coincide with the Class A liquor license rules.
Another odd law is that if you are under 21 and accompanied by a parent, you can drink in a restaurant, if the owner allows it. I don't know about bars but when my folks and sister (whom was 17 at the time) came up, we ate a a restaurant and they allowed her to have beer as long as my dad said she could. He didn't believe me until we tried it and the waitress brought her a beer. I don't know if there is an lower age limit to this.