Hello, I updated my meteor app in development from 1.6 → 2.2. I did it step by step from every version to the next with significant “Migration steps” or “Breaking Changes” in Meteor Changelog | Meteor API Docs . It was necessary to setFeatureCompatibilityVersion of the mongo DB three times like described here: Meteor Changelog | Meteor API Docs
That is a tough question. You moved over a lot of versions. Some of them with DB changes. First step would be to try on a test environment. Unless you are doing something special in how Meteor communicates with the DB and your MongoDB is up to date, then I would say is fine, but test it thoroughly please.
Fwiw, I went from 1.8.1 to 2.2 on my production environment. I did this all in 1-step. No major issues in the actual update. I scanned through all the changelogs and couldn’t find anything urgent.