2011 My partner and I Took the ferry to Europoort from there we stopped Hamburg then through Denmark across the Oresund Bridge/tunnel to Sweden. Visited my brother in Finland. Round trip back to Denmark
Ferry from Denmark to Northern Germany then North along the Baltic in Poland.
Cut South east skirting Czechoslovakia back to Germany finally Holland and home
3 weeks in total
Poland was very cheap for everything
Heard a few horror stories from a couple of German families but TBH we had a great time there
Denmark was indecently expensive ?15 for two ice creams!!!! They were very nice but................
Overall the trip (in June) was excellent with just 3 days crap weather, otherwise very warm.
Didn't venture further North mainly because of lack of time and I would be happy to go to Russia /belorussia if I was in a group rather than just the two of us (safety in numbers)
I would imagine Latvia Lithuania and Estonia would be ok if you keep away from the run down suburbs. (I have only flown to these countries)
Visa required for Russian federation incl Belorussia from London consulate
I know this is stating the obvious but pouring over a map and saying "yep let's go there......there and erm there.......When you actually do it you realize just how big some of these countries are!!!
If you do go...........Good luck and enjoy
Hope this helps