I do not worry, in general. So perhaps poor answer to your question.
In my experience, I tend to sleep in accommodations when in large cities. Most will let you store your bike (and obviously luggage) inside. In small towns or in "the wild", theft would probably be unusual.
Always keep your wallet/phone/compact valuables with you. Always lock your bike.
(Two panniers + a 60L dry bag... That's 100L... You could probably carry half or less.)