Also worth noting (if you don't know this) that on Fri/Sat from 17:55** the Robin Hood line is *completely* dry - e.g. you are not even allowed to have an unopened bottle of wine as a gift for later etc. - and I believe (though I haven't seen it) that they do sometimes search bags on boarding!
(Just thinking it was possible you might fall foul of this).
**As far as I remember
Well worth noting. Though from experience (living in Whitwell* towards the northern end of the line) they use discretion quite a lot. I’ve travelled back having had a drink and carrying a bag and haven’t had it searched. I think they can likely use intuition. Like I say, definitely worth pointing out.
* not one of the problem destinations according to multiple staff
)