I want to travel from Bruxelles (Midi) to London (St. Pancras) and return a few days after. There are no more seat reservations available, but I read in the forum that theoretically seat reservations can be booked at the stations as well.
Since I need 9h to even get to Bruxelles, I wanted to ask: how likely is it to get a seat reservation in Bruxelles for the Eurostar train?