If a Nintex Workflow (either a list workflow or a site workflow) is exported from SharePoint 2013 on premise, can it then be imported successfully into Nintex Worklow in a SharePoint Online environment?
Not at this moment, unfortunately. There are some differences that cannot be translated exactly in O365.
But you can post your workflow questions if you need help recreating the workflow in SP Online. I'm sure the community will be glad to help out.
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