Store the chicken, rice, and street corn mixture in separate airtight containers in the refrigerator for up to 4 days. Slice the avocado only when ready to serve. Reheat the chicken and rice until the chicken reaches 165°F (74°C). The street corn mixture is best served chilled or at cool room temperature and does not require reheating. Freeze only the cooked chicken and rice for up to 2 months. Cool completely before freezing in airtight containers. Thaw overnight in the refrigerator before reheating. Do not freeze the street corn mixture because the mayonnaise and sour cream can separate. For make-ahead preparation, cook the rice, chicken, and corn mixture up to 2 days in advance and refrigerate them separately. Assemble the bowls just before serving for the freshest texture.