Skyrim is a pretty good bet, since Bethesda reserved Rights for an Internet addres with "skyrim" in it. But maybe thats just to confuse People and the next game is taking Place on the Summerset Isles. Or maybe its the other way around

Bethesda is making up a Story about the Gods letting "Yokuda" reappaer. Yokuda was the Homeland of the Redguards before it sank into the Ocean for no apparent Reason. Bethesda is making a Story and a Reason up, Player solves it and Redguards can resettle in their old Homeland.
There are however, many unexplored Lands outside of Tamriel which could be claimed by the Tamrielic Empire. The Nords came from a Land far North. For some Reason, we dont hear from this Land anymore. There are still People living there, the first Nord Settlers got into a War with the Elves. Elves kill Nords, Nords get help from Homeland, Nords kill Elves.
There is Akavir, which appaerantly has a variety a non-humanoid intelligent Creatures.
Whats south of Akavir, east of Morrowind? Nobody knows...
Whats south of Elweyr and Valenwood? Ocean?
Being a seafaring Nation, the Redguards of Yokuda could have discovered Lands in the West, before their Homeland got a little too wet for comfort. In old Writings (Ancient Scrolls from the forgotten Library of Bladibla the mighty Mage and Scholar of the mythical knowledge, i made that up on the fly, of course it sounds cheesy, give me a break!) someone found in the ruins of one of the first Redguard Settlements in Hammerfell could hold Information of a Land in the West. With vast <whatever> and giant <insert creature Name>.
And of course, every new Land would have NPCs who are too stupid to solve their Problems, so they have to wait until an Adventurer comes by.