You have a fundamental misunderstanding of how all of this works.
The secure enclave takes your fingerprint pattern from the TouchID sensor and runs it through a algorithm including unique identifiers from the secure enclave itself, creating a token that is unique to that specific secure enclave.
Your fingerprint data cannot be stolen from the iPhone because it does not even exist on the iPhone--only the token is stored, and because it is unique to that secure enclave, it is useless anywhere else. That unique token never leaves the secure enclave, in fact there is no known path for it to leave. The only thing the secure enclave does is check that the fingerprint currently pressed against the sensor ends up with the same token as the stored token. The only data that leaves the secure token to the phone is "yep, it's a match" or "nope, it's not".
The misunderstanding is that you keep referring to it as your "fingerprint" being stolen, but it's not your fingerprint any more, it's the unique token. And again, not only is there no known way to steal that (because there's no path to that data from the rest of the iPhone), but even if someone got physical access to your phone, disassembled it, and pulled the token data out, it's completely useless data anywhere else. Nothing else is asking for, wants, or can even use that token for anything.
TL;DR:
1. Your fingerprint data cannot be stolen from the iPhone because it doesn't even exist.
2. The unique token that does exist is probably impossible to steal.
3. Even if that unique token is somehow stolen from the secure enclave, it is not useful outside of the secure enclave.