What pages are folks landing on when they do a local search? If it's the services page, you'll lose the ability to rank for those pages locally if you do a canonical. Are you showing up for local search terms in organic search results or local search results? If you go with a single site and dedicated local pages with local phone numbers, you'll be able to rank in both organic and local search results.
If your facility pages "tend to perform about the same as other local companies that are our biggest competition" and your goal is to gain an advantage, I'm thinking your best bet might be to grow your citations and reviews. I'm usually a big fan of consolidation so you can maximize the value derived from your SEO efforts, but it would be very disruptive to transition to a single site. Is management prepared and willing to shoulder that?
If you're not ready to rock the just boat yet, perhaps you should do an apples to apples comparison of your local facility sites to your competitors to see if a boost in citations or reviews could help bump you higher.
I'm just not hearing a pressing need from you...