I'm trying to make a reservation for the sleeper service from Prague to Warsaw on 28 June; I think 60 days is the furthest you can book in advance for PKP services and that's around ten weeks away, so is there any better option than repeatedly checking over the next two or three weeks to see when reservations become available? Is there a noticeable price difference between booking via ČD, PKP or ÖBB / others? There's also a reference to closures between Lipník and Hranice; would that affect the overnight service?