I think I would go with the following....
Ep 1. - for obvious introductory reasons.
Ep 3. (Midnight chase) - first major battle sequence, move from Tostenwald and the team begins to gel.
Ep 8 (gates of Zadash) - introduces the Zadash/knights of requital act
Ep. 11 (midnight espionage) - definitely top 5 episode of the campaign.
Ep. 26 Found and lost - no spoilers, wont do it.
Ep 28. Within the nest - welcome Cad Clay
Ep 29. The stalking nightmare - the rescue, the win
Ep 40. Dubious pursuits. - running out of room and this is a good one to show the piracy arc and the Fjord Avantika dynamic
Ep 42. In hot water - best battle so far, Beau shows some growth, “snap”
Ep 49. A game of names - the big Caleb Nott reveal.
Obviously you can’t include everything, but these are the ones I would go with to give the best overall view of the campaign.