License question when moving license

I have 5 machines in the office, and 3 of the machines is using SU2018, now one of the user is away for 4 weeks, I know I can deactivate his license and install/activate on another user, but my question is, do I need to remove the software from the deactivated user;s machine also even though it will not work without a license, or can I simply leave it on and then move the license back again ? I will only ever have 3 users running SU2018 at any one time but removing and reinstalling is a pain when they need to jump machines especially with Vray installed (all three license on dongles so we can unplug/plug at will).

As long as you have your license info to hand it is about 3 clicks to remove and reinstall.