I guess i will just fly again this year.
Well, there are some slight chances that situation with rail connection to/from Greece will change, though we'll need to wait till summer to see. At the same time, it makes sense to mention that there are a lot of things & places to see in Macedonia and Bulgaria, so (if you have time) going by land with changes isn't extremely bad option, because you can always make a day/overnight stopover somewhere, kind of break the long trip