Thank you for your question
The simple answer is - it is too early to tell.
However the realistic position is that nothing at all will happen in the next 18 months - and the odds are that if we wish to have a trade agreement then like Norway we will have to accept the free movement of people.
In the last resort you can apply for Leave to Remain in the Uk based on the length of time you have already lived here
please ask if you need further details