First I divide exported file in chunks, my file is 1MB and have around 200 entries, but my ADSL upload speed is only 200 kbit/s.
Second I fix some entries when they can’t be exported with WDG HTML Validator – Direct Imput, just copy there exported message in body and click validate. (In mu case a “” was needed around href in <a> tag)
Finally I check all links a reffer in Workshops, some I fix some typos during fixing links
What if you ca’t import even after validation ?
Simple use copy-paste int into new entry (Yes this, way you will lose a original permalink !!!)