Hi Miriam,
I run a multi-city domestic cleaning company and am facing similar challenges. Because we do all our work on-site at clients' houses we just use a storage unit in each city as our base of operations - much more cost effective this way.
We are able to receive mail at each of our locations (a service the storage locations offer) but do you think using these storage unit addresses as our physical locations in each city would get us into trouble with google?
best Adam