Just as a follow-up on this -- I discussed CGMs with my diabetes educator and, as I expected, it turns out that my insurance won't cover it at all. She did give me a sample Dexcom 7 sensor that's good for ten days that I'm seven days into, and it's been interesting, but not as informative as I'd hoped about spikes. That's because most of the spikes I've seen haven't had any apparent cause that I could figure out.

I'm contemplating getting a set of the OTC Stelo sensors (made by Dexcom, but not called CGMs because they're not FDA-approved) for the cruise I'm going on next month because that will give me feedback for any indulgences. Those run $100/month, which is annoying but mostly affordable.