Border Response Resilience Act This bill requires the Department of Homeland Security (DHS) to develop a plan for responding to irregular increases in migration at the border that present risks to border security. The plan shall include various elements including (1) a list of each agency, component, and office involved; (2) a process for quickly expanding capacity to temporarily process and hold individuals; and (3) a strategy for coordinating with local governments and other entities when DHS releases detained individuals. DHS must also identify metric thresholds for determining when to activate the plan and must activate the plan when such thresholds are satisfied. Furthermore, DHS must notify Congress no later than 14 days after activating the plan.