exiftool -q -r -if '$MIMEType =~ m{^video/} and
                        $ImageHeight < 1080 and
                        print "$Directory/$FileName\0" and 0' . |
      xargs -r0 echo rm -f

Would remove all videos whose Image Height is less that 1080 pixels (if you removed the `echo`) in the current directory, recursively. That assumes file names are (properly) encoded in UTF-8 (though see the `-charset` option for other charsets).

Instead of piping to `xargs rm`, you can also store in a file (`> list`), to do some inspection on that list first:

    xargs -r0a list ls -ldrS

If it looks fine:

    xargs -r0a list rm

Or store the information in JSON format so you have all the relevant information in an easily readable and parseable format:

    exiftool -q -r -j -if '$MIMEType =~ m{^video/}' \
      -ImageWidth -ImageHeight -VideoFrameRate -MIMEType . > list.json

Then review that list, and delete based on some criteria:

    PERL_UNICODE= json_xs < list.json -t none -e '
      for (@{$_}) {
        unlink $_->{SourceFile} if
          $_->{ImageHeight} < 1080 || $_->{VideoFrameRate} < 60

(note that I found that for FLV files, it was `Videoframerate` instead of `VideoFrameRate`, you may want to watch out for this kind of inconsistency).