The boutique told me the Nudo rings can’t be resized because of the design. It’s imperative you try on the rings in person before you buy
I don't know where you're located but I took 2 of my 3 Nudo rings to Pomellato store this morning and they are resizing them (bigger) because in the years my fingers have swollen a bit and they are too small. It costs 160 euros each one and will take 7/8 weeks. I'm in Italy by the way.