Milecalc.com is one of my go-to sites; it calculates considering 500-mile minimums (but you need status for this "benefit") whereas gcmap will calculate straight distance. So, with status, YYZ-YOW-YUL-LGA nets 1500 SMs. Each way. Now this routing will put a kink in your schedule.

Another option which you may have to build a business case for is buying a personal unlimited flight pass which will offer a set number of status miles per month. Of course, this is not available from Concur.