The fact that the films had a poor box office reception is not necessarily a bad thing. Usually poor box office performance is an indicator that the film is a bit stinky, but in this case I'm kinda glad that the majority of people didnt like it.
They wouldnt be exploitation films if everyone liked them!
They could have done parodies of gringhouse movies and cleaned up the dirty bits, toned down the violent bits and put on minimal and superficial degrading artefacts (scratches, dust, popping audio) that would have made the movies appeal to a much wider audience.
Instead they made pastiches of grindhouse movies with all the extreme humour, sex and violence and rubbish stories/special effects that go with it. The trailers and the degraded images are one thing to make the film look vintage, but to actually remove a reel from the film is a major narrative decision, that will piss off most people who go to watch it but will entertain the few people in the audience that the film was made for.
I can't wait to watch it!
I would like it if they release it as a double bill, mainly becasue I have never been to a double bill before and think it would be fun. But I think that the fact we don't normally have double features in the UK will have more to do with how the film is released than ticket sales.