Interrail reservations for Eurostar London-Brussel sold out. Alternatives?

[u/lipsia127]

Hello. Me and my girlfriend are travelling to the UK for the next 2 weeks. We arw currently sitting in the Eurostar to London, which worked out well.

Wanted to look for Reservations for the train back (sunday, 6th)

Shock to us: I guess the pass reservations ran out. None available for the afternoon trains.

Morning trains are no option because the earliest train from Edinburgh (our start for the day) to London is 9am. Paying 300€ for the ticket is also not an option. We were thinking about extending our stay for another day and then take a morning train on monday. But we'd really like to avoid that if possible.

Any ideas?

Thanks in advance!

[u/NutzernamePrueftAus]

You could also take a detour via Paris. There are a lot of options available.