TeraByte Unlimited

Hi - I just upgraded my system, with a Samsung 970 EVO M.2 boot drive - previously, I've been backing-up using TBWin, and restoring using a TBWinRE boot CD
Will a TBWinRE boot CD be sufficient for restoring a backup to a M.2 drive ?

Yes. If the system is using NVMe RAID you probably need to add the RAID drivers to the TBWinRE build, but other than that it should be just like a normal drive. Boot to the TBWinRE CD and check if it sees the drive okay. (I assume you're using a Windows 10-based TBWinRE.)