Operation in GNSS-denied areas is already a stock feature on many relatively inexpensive commercial drones. The manufacturers talk about it euphemistically for obvious reasons, but they're designing drones specifically for the Ukraine war. There's a huge amount of engineering effort going into building drones that can remain operational in an extremely hostile RF environment.
Compensating for wind drift is a fairly straightforward software problem when you've got a fast processor, a bunch of high-resolution cameras and a laser rangefinder.
If you have a downward facing camera you can track your movement like an optical mouse by just watching the terrain. Error will creep in, but you only need to fly a few kilometers till you find something that looks like a strategic bomber.
