I'm a solid walker, and I could do it. I don't know about you. Mary and Tito's is at least a mile away. El Portal is right in Old Town and isn't bad (but I haven't been there in years because it isn't screaming good, either).
Drive to Mary & Tito's - get the carne adovada with red chile and an egg on top. Enjoy yourself. It's worth getting in the car and driving a short drive to have exceptional red chile. How often do you get the chance to have it?