First, the caveat: Rapid7 does not officially market a "USB stick" version of InsightVM. However, the is incredibly flexible. You can install the InsightVM Engine (the scanner) on a Windows or Linux laptop, run it locally, and even use the console in a disconnected mode for a limited time.
Ensure your host has at least 16GB of RAM and sufficient disk space (typically 80GB+ for the database). rapid7 insightvm trial portable