I was looking to use mine around April 6/7 2026 on Icon - the website says "spring break" is blackout - but doesn't define what dates are SB. But I noticed yours just says NYE/XMAS blackout.
I've heard Royal might offer a shuttle to take you to the other port, but I don't recommend it as they usually go to the airport first for drop off. Spend the $35, jump into an uber and go straight to the ship.