I'm working off two wider reading texts for Prose, poetry and drama. My prose texts are Shelley's "Frankenstein" and McEwan's "Enduring Love", my drama texts are Shakespeare's "The Winter's Tale" and Williams' "A Streetcar Named Desire". My poetry consists of Duffy's "The World's Wife" anthology and... well honestly lots of other bits and bobs.
Honestly, I don't see why people are attempting to memorise vast amounts of wider reading. The markscheme for the exam states that marks are gained in 4 Assessment objectives. Wider reading is one of those objectives, worth 10 marks out of 40. It's also worth about 3 marks out of 10 in the contextual AO, so that amounts to 13 out of 40 marks, about 30% as people have said. Really, that's not an awful lot. The examiners aren't asking for people to have a perfect set of wider reading texts to bust out in the exam, just have the knowledge to comment appropriately on some wider reading. The vast majority of your marks are going to be picked up from analysing the two texts in front of you, so unless people are reading this vastly to gain a greater contextual knowledge, you may as well calm down and refine your reading. You are expected to look closely at one piece of wider reading for each genre, rather than drop in the names of 4-5 texts, briefly mentioning them, so you will pick up a lot more marks from looking at a couple of wider reading texts and being able to reference and quote from them, rather than spreading your reading so thinly that you can barely remember the individual texts.
Of course you need to use a wider reading that suits the theme of whatever the question may be, but there are really only a couple of extremes and by choosing the texts you look at with reasonable care you can pick texts that cover a wide range of themes. Remember it doesn't have to be a comparison, talking about your wider reading as a complete contrast to the themes of the question can work just as well if you can take into account the context of the texts (Not just historical context but textual context, context of writer, etc). Hypothetically if I had only studied Shelley's "Frankenstein" and the question was themed around parental love, I could quite easily quote and reference from that. However if the question was focused on passionate/sexual love, I could use Shelley's "Frankenstein" in context to show the changes in how love is viewed over the ages. One wider reading text can be bent a lot of ways and though I don't suggest using only one from each genre, going for anything above learning 3 from each genre is, in my eyes, a massive mistake.
tl;dr - Calm down, you don't need to study 300 texts, just know a few in detail.
EDIT - From what I can gather, it's a relatively new spec and the only two previous exams have grouped two poetry extracts and two prose extracts together for the first question (I can't remember what order sorry) so it's likely (but NOT a certainty) that we will get 2x drama extracts for the first question.