if you can double your bitcoin in any way i'm sure the price will tank to 50% of current price long before you can do anything
It won't work.
If XT is adopted, XT wins, there's no other chain, or at least there's no other chain with value.
You may find someone that lived in a cave for the past year and scam them using the abandoned chain, but that's not something you'll want to brag about, I think...
what happen if both chain hold 50% of the network?, it's like having a bitcoin with half the network and a new altcoin that want to be bitcoin 2.0
Fork doesn't occur under those conditions.
People's choice will be clear and every service will update software in proper time if a fork does occur..