Have a wonderful cruise! I know you're thoroughly enjoy it.
And definitely don't worry about the suit. On a regular basis I'll just take a blazer and Dockers. I'll wear the tie on formal nights and if I find the dining room a little chilly, then I'll wear it without a tie on other nights. You'll be fine!
And let us know all about it when you get back.
47 Cruises & Counting! Favorites: Paul Gauguin to Tahiti: Uniworld River Cruises in Europe; any of the Celebrity Solstice-class ships; Holland America for 12-nights in the Baltics & Russia; RCCL for 14-night Greek Isles, Turkey, & Croatia; Holland America for 14-day Alaska cruisetour; 10-night Canada/New England cruise; 21 days in Hawaii including a 7-night NCL cruise; Oceania for 25 days in Asia; & 3 months touring Europe by train. And many days spent in all-inclusive resorts!