The hints we've gotten so far seem to indicate that Itsuwari no Kamen is that it is clearly a sequel. The events of Utawarerumono were pretty obviously referenced. Whether it is historical fact or legend is still up for debate. How far in terms of distance this new village is from the ones of the first series is also not clear at this point.
It's certainly not a direct sequel since it seems to stand on its own.
I'd lean more toward recent but physically distant than occurring long after the first series. I don't ever remember seeing snow in the first series.