http://portableapps.com/https://en.wikipedia.org/wiki/PortableApps.comDon't know if that would isolate your activities enough. IT would still see your network activity BUT now you'd have apps that didn't PRESUMABLY leave a trail on your computer b/c they all run from the thumb drive. Get something fast and big if you need to buy a new thumb drive. A USB3/32GB is plenty, more is better.
Beware of looking like you are performing corporate espionage though...
I know people who use these at college/university so that they don't have to rely on computer lab software for email (email goes with you), browsing (bookmarks and history go with you), and office (LibreOffice, might prefer LibreOffice over MS Office, I do).
Extensive movie, music and audiobook collection on your phone? Thumb drive?
Write a book using PortableApps LibreOffice Writer or FocusWriter? Save to your thumb drive.
I had a similar situation at a previous job. Automated the heck out of the job, lots of down time. In the end our IT support questioned the amount of bandwidth I was consuming. I had a partially legit reason and backed off on how much I was streaming (audio and video). No further problems. i was using YouTube for music, tutorial videos, etc.
Then spent time improving my computer skills on software like 2D and 3D-CAD among other things. Left for greener pastures with these new skills some time after that. Took my self-created automation with me b/c they lied to me repeatedly (false promises) and paid low market salaries. Went across town to the next job and never looked back.