I want to take my only computer offline. Is there a way for me to get updates/fixes without the Command Center? I'm wondering if I can perhaps download on, say a public PC, burn the download to disk and transfer into Sonar from said disk. I would really like to lockdown my computer to only allow Win 10 x64 and  DAW software to run.

The installers are in https://www.cakewalk.com/My-Account/Products
 

You can download from anything to (for example) a USB stick, then use that to update your offline computer.