Great job nice and neat , gotta be happy with that.
What you dont want is voltage drop, do some maths
maybe 25mm like Winnie suggested.
remember all these members have already done this so
they know whats right and what works
@Cuppa has an extensive electrical set up in his canopy setup.
Check out his build thread youll find most of your answers there
Im sure, or just ask, easy as, TD