So far the only idea that I've read about and might feasibly result in uploading instead of copying is gradual replacement of each cell by a nanobot simulating that cell. So at the end of it, there'd be no bag to change its mind.
You can likely replace the large "functional groups" of neurons instead, with the group size threshold being the maximum that doesn't meaningfully affect our consciousness. This might well be many billions of neurons at a time.