Hello @PallantHouse,
Thank you for reaching out to the Docusign Community, where amazing Community members and Moderators are always ready to share knowledge with you.
I understand you're looking for guidance on temporarily assigning a seat. Absolutely happy to help!
One approach would be to close the existing user temporarily. This would free up a seat, allowing you to add a new user. Importantly, when the original user returns, you can easily reverse the process - close the user account and reactivate the original user.
Remove Users from Accounts | Add Users to Accounts | Reactivate Users
However, since you'd like the new user to have access to the previous activities, I recommend that the user temporarily change their Docusign email to the new user's email address instead. Upon their return, they can change it back.
Change Your Email Address
I hope the recommendations above works for you. If it did, can you please mark it as "Best Answer
"? This help other users with similar questions find the solution more easily? Let us know if you still need further assistance.
Regards,
Melanie | Docusign Community Moderator
If this helped, feel free to click "Best Answer"!
Hello @PallantHouse,
How are you? I'm checking in to see if the solution I provided has been helpful. If it has, may you please mark it as Best Answer
? This will help other community members with similar questions find the solution more easily. 
Let us know if you still need help or if anything else comes up, we’re here for you!
Sincerely,
Melanie | Docusign Community Moderator
If this helped, feel free to click "Best Answer"!