I have projects from 7 years ago that got dependencies stuck on an old major (that's the default) and the webpack I put there in 2013 still successfully builds.

I have projects from 7 years ago that got dependencies stuck on an old major (that's the default) and the webpack I put there in 2013 still successfully builds. The original versions are noted in package.json, so all you might need to do is fix it to the minor/patch (1min task with search/replace). I wouldn't be afraid of parcel - you can do the same thing.