My husband traveled with carry on and was able to bring a tux which he wore with the usual formal shirt, cummerbund etc. He brought well shined black loafers..these he could also wear every other night. For excursions he had good walking shoes which he also wore on the plane. He took a blazer, grey flannel trousers, 2 button down dress shirts, a couple of ties, 2 polo ****, two khaki daytime trousers, a neutral color cashmere sweater, sometimes a fleece jacket or rain gear. He also packed easy to wash out socks and under gear. Allowed size toiletries rounded out his packing. He always dressed appropriately and looked great. I got a kick out of how proud he was of himself. A few years ago I have started traveling with just carry on, and while it can be bit of a challenge, I like a challenge.
I think our success at managing and actually enjoying the Silversea dress code is why I get a little and sometimes a lot irritated by the constant whining over requested dressing.