Our family holiday is to Brittany in August, the campsite has a trout river that can be fished and I have permission to take my fishing gear

So I need some advice - I am just about to complete my first year of fly fishing, do you think I can get away with using the gear I have on this river? (Greys GRXi 7/8)
It is a river rather than a tiny stream and I am used to stillwater fishing at Elinor & Grafham. Also, while the wife is letting me take my fly rod I don't think I can afford or get away with (more importantly

) buying some new gear for one trip.
Your thoughts please, or should I not worry and just give it a good go?
Cheers, Mark