The Eurostar train goes through the channel tunnel from London Waterloo Station to either Brussels or Paris. Then you can use the eurail website to get connections from there. If the person traveling is from outside Europe, a Eurail pass can be obtained for the travel from Brussel/Paris to Poland, but the Eurostar isn’t included in the pass.

We get the coach to Gdansk from Victoria, it leaves about 3 times per day, is clean, comfortable and not too harsh a journey if the gentleman is fit and fairly robust. Not sure my mother would like it, but if he not into flying well worth considering.

i think that going by car would be the best but keep in mind that a good car will most likely be stolen…you could in fact leave the car in germany and continue by train or hire a car in poland…………….make an adventure of it if you have time and go to HULL and cross over to HAMBURG over night leaving car or taking it………..if you go by car then stop over night in guest houses(gast haus) ,they are like our pubs in as much as that is where people go for a beer and also to eat…..i stay in places in the countryside away from cities when in my car but on a train you can,t do this and i understand that from north germany to moscow is very flat country side and may be boring and you are stuck with it ……with a car you have freedom to stop for a pee when you want ……to hell with it.TAKE YOUR CAR ha ha

feed him a bottle of whiskey and take him by plane. we all hate something, its better than driving for 30 hours. and believe me, im not being flippant. it only takes an hour or two. any other method will be very tedious. get it over with quickly

This story is so familiar to me that it’s unbelievable.
I live in Mazury about 180 km’s south of Gdansk.
My mother is 80 years of age though in poor health.
We eventually got her on a plane with the help of a whiskey or two. It was a tough trip for her and she was tired out when she got here.
Your 85 year old may be in good health, but having done the trip by car several times myself at the age of 40, I think It may be too much for the old man. Don’t get me wrong here a lot depends how you go about it.
My first trip here by car at the age of 40 was done none stop from wales to lodz 24 hours in total. wales to Dover to callais then Belgium, Holland and Germany,crossing the border into Poland at Swiecko. I have done the trip seven times in all.
At the age of 47 I did my last trip, this time with my 4 year old and six monthts old sons.We took three days stopping over night in Holland on day one then just inside the Polish border on day two. Day three was the worst which was driving through Poland to Szczytno.
It does not always go to plan Our worst trip when I was about 42 took 36 hours. If it could go wrong it did go wrong just something to bear in mind. One time stuck in traffic in East Germany for eight hours. That would be tough on an 85 year old
Its easy to find hotels Motels etc on route.
Driving is easy untill you get to Poland, then it just gets so slow stuck behind tractors, horses and carts etc.
My mother has done the trip by plane twice now and god willing is due here in July.
Even if the old man went by Plane its still 160 km’s to your destination from Gdansk.
My advice if going by car would be to allow four days for the traveling, and if the old man is ok keep pushing on and maybe get there in three.
The best piece of advice i could give you would be to talk the old man into flying.
Good luck!
Ps if you need any more info.I can be contacted through this link to my home in Mazury.