Clone the original flow and change the event trigger to the klaviyo native AddedtoCart event.

The people already in the flow would continue in the flow as long as the emails stayed live. If you turned them to draft or deleted the flow, they would not continue to receive the emails.

One option could be to add an extra time delay to the original flow, say an additional 15 minutes.

Then, add a flow filter to the original flow that says "what someone has done > has received email > where flow equals > [cloned flow name] > zero times in the last X days"

That way, new profiles will receive the cloned flow and be excluded from the original flow-- but current profiles in the original flow will continue through. Once all of those profiles have made it through, you can set the emails to draft.

The key here is the extra time delay plus flow filter on the original flow