WARNING: [11:57:14][Import-DbaCsv] Failure | The given ColumnMapping does not match up with any column in the source or destination.I then added the -AutoCreateTable option and my file was imported. This used nvarchar(max) columns, but that was fine. I could use a quick loop to import all my files. This was by far the easiest method, as the existing table didn't cause me issues. Once I imported the first file, I dropped the option and had all subsequent imports sent to this table.

I didn't try the Import-Csv cmdlet, as I'd then need to do my own manipulation to get the results into SQL Server.