I do not really want a Sequel. Works like "The Handmaid's Tale", "1984", Fahrenheit 451, they're about transmitting a idea, a concept of a society gone wrong somewhere.
They're not about Worldbuilding.
Worldbuilding and theorizing is fun as heck, and it fits perfectly with many franchises.
But the more you scrap for details and dates and singularities of Gilead, the more you dilute it's core message that it's about the dangers of a fundamentalism everywhere.
This.
That's why I don't like the show very much, because it's stretching what is fundamentally a very simple, deliberately detached-from-specifics of time and place story into this full-on
Game of Thrones thing. And while
some shows have done excellent social commentary with that (see:
Star Trek: Deep Space Nine), Atwood's original work, like
Oryx and Crake and
1984, is fundamentally a parable rather than a detailed allegory. DS9 creates a world--mostly whole-cloth, it must be noted, with only the broad strokes of the Federation, Klingons, and Romulans that we already know being out there as the background for the initial focus on the Bajorans and Cardassians--and uses it to tell deep, nuanced stories of oppression and the internal society of the oppressors, stories that we probably can't get today given the hyper-commercialization of media, the power of studio executives, the obsession with
Game of Thrones shock value, the radicalization of social-justice movements through sites like Tumblr to the point that, say, DS9's
Duet would be condemned for portraying people who were involved with crimes against humanity as anything less than one-note villains.
The Handmaid's Tale isn't like DS9. It's fundamentally a story like 1984, that isn't meant to be plausible but is intended to teach a lesson using vaguely recognizable places and terms along with scary-sounding new terminology to show the reader that fundamentalism is a very dangerous thing.
So, yeah. The more you do with the work and the setting, the more you erode the power of the original work itself.
That said, if you're going to do something inspired by it, that's fine! A multi-way American Civil War featuring theocratic fundamentalists? That would make boatloads of cash and if done well would be a powerful piece. Just...don't try to stick to this particular established canon. It's not meant for that and it'll only result in a flop.