This comes as a feature request from one of our Enterprise users. If you want to leave a domain to expire but keep the content and move it to another blog, then Clone blog will make your life a lot easier.
Clone Blog
Go to the blog you want to copy the data to, or create a new blog. In the top right, click the three dots and select Copy data from blog.
Choose your blog from the dropdown.
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This will wipe the existing blog and copy the data from your chosen blog. Give it a few minutes, keep an eye on the Activity log and it’ll be finished without any hassle.
Hope it helps and keep the feedback coming!