I think it would be a good plan to cut down on the CGI budgets and produce two more movies... one on the Spengler family and then an old school movie with the O.G actors. I think the studio would see that not even Paul Rudd and riding Finn Wolfhard's stranger things buzz is enough to make them money from the Spengler family. The O.G actors movie could work with someone like Wes Anderson on a small budget. I'd put decent money that even if it's a Hudson led movie, but with significant time for Aykroyd, Murray, Potts, Weaver, Moranis, the studio would make a hefty return on investment. It doesn't need big set-pieces, it just needs time and space for those actors to breathe. That crowd solving a small scale haunting could be easily be a great movie which can also introduce a new team as Hudson says.