Ridgeway Plaza is not considered downtown, but certainly is within walking distance to many areas. Like most things reasonable distance is subjective. If you are used to being in a city than a reasonable distance to anything is less than 10 minutes by foot, at least by the measures in urban planning.

Glenbrook and Springdale are both walkable interesting neighborhoods with an old school neighborhood vibe that also have walkable apartment to grocery store areas. There are no grocery stores, unlesss you count Target in the downtown, and none in the south end.