It looks like the upside Down is set to manifest itself in the pages of the comic as Dark Horse Comics has announced it is creating a mini-series along with Netflix to produce. The narrative looks like it will be filling in some narrative gaps as well, following the time Will enters the decay.
Stranger Things #1 (of four issues) follows Will Byers as he enters a dimension of decay and destruction where he must use his wits and resolve to dodge the pursuit of the Demogorgon and escape the Upside Down. Stranger Things #1 features a cover by artist Aleksi Briclot (New Avengers, Maskemane) with three variant covers, one each from Rafael Albuquerque (American Vampire, Blue Beetle), visual artist Kyle Lambert, and a photo-variant cover designed by Patrick Satterfield and Netflix.
Stranger Things #1 goes on sale in comic bok stores come September 26th 2018