It gets cold in Toronto, doesn't it?
There is a fair to good chance if you have an R610 on your inside wall towards the office (like near a window),
and the R710 on the facing side of office (like near a window), they might Mesh ok, supported by Unleashed.
Other factors would include what kind of auto/truck traffic goes thru the alley, and what kind of communication from the office (VoIP? or just browser/email).