I wasn't able to crop or draw image without keeping aspect ratio.
using (var html = new HtmlConverter())
{
PdfImage image = PdfImage.FromImage(html.FromString(htmlText, ImageType.Bitmap, (int)textFieldbounds.Width, (int)textFieldbounds.Height));
page.Graphics.DrawImage(image, textFieldPosition.X, textFieldPosition.Y, textFieldbounds.Width, textFieldbounds.Height);
}
but for large html markup it's looks very ugly. Something should be defenetely readable (like order number, but description can be cut).