I booked a holiday around the Baltics for 2 weeks Today for August and back in September.The agent told me that if you book any holiday after October, you will need a visa. If you are over 70, it is free or if you are under 70, you pay.
When we went to Russia we needed visas which were very difficult to get and 500 pound each unless you knew a way to get it free like us.
This visa requirement is because we left the EU.
It should be an easy process so wait for October to find out.
2 weeks on a ship with balcony cabin was low cost at 3700 pounds for 2 leaving Southampton and it should still be warmish deep into the Baltic sea area.
You will also need visas anywhere else you travel and the USA visa took many hours with photos and fingerprinting in New Orleans.
Those having a Northern Ireland passport don't need an EU visa as they are still in it