'Of Mice & Men' has been keeping people busy with its layers well beyond graduate level for nearly 80 years, so I do think it's a shame some are so entrenched in the conviction that there's nothing much for a bright GCSE student to go at.
I've found a couple of interpretations - of a passage I could recite by heart - in exam scripts this evening that have been entirely new to me, & I've been teaching it right across the ability range for 15 years & examining on it for 5.
To be honest, I'm perfectly happy to have a break from it. It's not a personal favourite!
Oh & setting wrt reading whole long texts - yes, I would certainly expect higher sets to read large chunks of a substantial novel independently. One or two won't, & will probably crash & burn unless they are particularly brilliant at extemporising & particularly lucky with the exam questions.
Apart from anything, if they're really turning up at University bemused by the notion of sustained independent reading, we aren't actually doing them any favours by reading whole texts in class every time.