Extra code in WordPress.com export killing import

Trying to import a blog from WordPress.com to self-hosted. Lots of experience doing it, but never ran into this problem before. Posts are only importing part of the way.

I looked at the .xml file, which has the entire posts in it, and when they’re broken they appear to break due to either an inappropriate html tag (like <span> </span>, whether or not there’s text in the middle) or a bad character (curly quotes/apostophes) Other times the html tags, at least, are fine.

I did some manual experimentation on a few posts and when I took out the improperly-styled apostrophes, dashes, and removed all the useless spans, the entire post imported fine.

Does anyone know of a way to force WordPress just to accept the code? I can do find and replace for the curly apostrophes, the em dashes, etc, but I can’t find and replace all the bad spans, etc, that have crept into this blog over the last few years. (There are a LOT.) I’d have to do that manually on 570 posts.

And does anyone know if there’s a method in Notepad++ to delete a pair of tags at the same time? Never looked into it because I haven’t had to do it on such a large scale.

The affected site is https://funny-about-money.com , if you’d like to see how it breaks things off.