Strasbourg is a fairly small station and last time I was there the TGV and TER to Basel were next to each other (cross-platform connection). Honestly you should be fine!

EDIT : are you looking to take the night train leaving Milano Porta Garibaldi at 22:13 down to Salerno ? This could be tighter as you have to walk 30 min or take the subway from Centrale (contactless payment possible).

I guess you're coming from further than London and can't take any Eurostar earlier than 09:31? I'd always try to have some margin before a night train.

I'm coming up from the SW UK. Last year I did as you suggested, spent a night in Reading and coached into London to get the earlier Eurostar. Then Zurich and Milan for the night sleeper down to Bari for the ferry to Greece. With the St Gotthard and the French route out it takes a bit of jumping about.

​​​​​​This year I'm spending the night in Milan as the sleeper doesn't gain much - it's an evening ferry. It's just a question of getting to Milan early enough for a decent supper and night's sleep...

Okay understood, all good then! :)

You won't get stranded along the way unless things went terribly wrong. There are a few later options via either Brig or Lugano in case.

Yes I agree, the Gotthard base tunnel disruption + the French landslide both at the same time are quite annoying. Fortunately the Gotthard old route is still running and the Lötschberg/Simplon railway is too (although that one will remain closed for 3 months due to works this summer).

Remains the beautiful but very slow Bernina railway... :)

I came back over the Bernina pass on my way home last year. It is beautiful. Going down I switched at Lugano to get a quicker connection to Milan and catch the Bari night train.

Cheers