First off, apologies if this post is a duplicate - the only close item I found was in the How-Tos, and referred to a fix that appears to be on-prem only. I'm looking for a way to preserve the workflow task history that Sharepoint purges after 30 days. Is there a way to generate via workflow a copy of each task item to a separate history list, that references the original item it's approving?
@bwilson yes that would be the way to achieve that. You could either run a workflow on the history list and create a new item in a new list when it was created (adhoc) or you could run a site workflow that would copy the items over to a new list in batches and do so say weekly.
Good luck with your endeavors