Combine reports across tests

Scenario:
I'm running backstopjs tests in CircleCI environment, and I want to take advantage of parallelism by splitting up test config into multiple parallel runs. For example, each backstopjs run may contain just 1 or 2 scenarios, but I'm running 20 different scenarios at the same time.

Problem:
Each test generates its own reporting, which is tedious to comb through.

Desired solution:
For any given number of test runs, generate a single combined report, so that I can more easily assess visual regression results.

Is there an easy way to get at this?