Does that even make sense with the current transaction times and fees? You are going to pay more for the fees than for your meal. Unless the fees go down drastically, it makes no sense to use bitcoin as a daily payment method.
Here in my country, if the wallet to send the payment and the wallet to receive are both a wallet of coins.ph, there is no transaction fees, so it will be better here in our country if the McDonalds will use and for sure they will use the local bitcoin wallet. Then that's a great news for us here.