Questions I'm having difficulty answering on my own pertaining to Ashlander's in the 4th Era. (For RP purposes)

After the eruption of Red Mountain and destruction of Vvardenfell, are the Ashlander tribes for all intensive purposes done for? Since they're nomads, the amount of ash in the atmosphere would disrupt the wild life thus wrecking their lifestyle i.e. food, shelter, clothing, weapons, armor etc. Over the course of the time from the eruption to the events of Skyrim, would their numbers have dwindled drastically and have the last few Ashlanders of each tribe surviving by a thread? I think they would strongly, perhaps desperately clutch to their ancestral worship in these very difficult and challenging times. By turning to ancestor worship for answers and solutions, the Ashkan's power and influence might decline as the Farseer's (the wise woman, or shaman of the tribe, also an Oracle) would grow.

With the strong dislike of foreigners and the Empire, would the Ashlanders view of the Dominion be that of Soviet Russia with the Allies in World War II (the enemy of my enemy is my friend)? I'd figure the Dominion would view them as barbarians who could be of no use to them since Vvardenfell is 1. Destroyed via Red Mountain, and 2. The distance between Summerset Isle & Morrowind. A question to counter that, since their ancestors fled from Summerset Isle to Morrowind, is there a deep rooted dislike towards Altmers as well? Thoughts or comments?

The psyche of the Ashlanders would be shaken because of the eruption of Red Mountain, causing Vvardenfell's population to move to Solstheim and even settle in eastern Skyrim, would it also cause them to possibly move with the displaced population or stubbornly remain in their homeland and adapt?

The one significant event that changes their lives and future is the eruption of Red Mountain. The Great War & the turmoil inside the Empire and Tamriel would reach their ears, and maybe have them rejoice at their loss of power and stature. Possibly even striking out against them, but I think for them life would go on whether or not the Empire collapsed or survived.

Any constructive thoughts, comments and ideas are greatly appreciated!

Well I have a few thoughts to add to this. Take them as you will.

The Ashlanders are perfectly adapted to deal with things of this nature. Culturally and racially(clothing choices, lifestyles and Fire resistance and Ancestral aid when needed) It would be tough though, and gauging the destructive power of the Red Year is difficult at best and impossible at worst. An event of similar magnitude to the Red Year happened before though. It was called Sun's Death I believe and it was a massive volcanic eruption that occurred in the 1st Era or so. I believe that event to be worse than the Red Year given that that year was called http://www.uesp.net/wiki/Lore:First_Era#1E_668 by the Khajiit, I believe, because the eruption was so vast it blocked out the sun for almost a year all the way to Elsweyr and beyond. http://www.uesp.net/wiki/Lore:Flora_N was created because of this event. There is no mention of any Sun's Death level effects on the rest of Tamriel so I must conclude that this event was more catastrophic than the Red Year eruption. However any ashlanders anywhere near Vivec City, now known as The Scathing Bay, would be totally obliterated. However given the Foyada and their likely funneling of lava flows I think the Ashlanders would be mostly intact as a people even if quite a few of them were killed and hard times were felt by them for years. I could still see them eeking out a living in the old Ashlands. They did survive the Sun's Death event after all.

If the Ashlander Tribes have survived, they have been tending the green pastures in the shadow of Red Mountain for at least a century in peace.
The Northern Tribes of Vvardenfall that were dealt with to be named Nerevarine may have survived the actual eruption, and the Argonian Zombie Apocolypse by living on northern islands in the Sheogorad Region. Solsthiem and Dagon Fel(?) were where many Refugees from the Great Houses also fled, they are willing to use boats to survive, and they have never gotten on the bad side of Azura.<--- They may have known ahead of time, unlike most Dunmer.

It is worth mentioning that volcanic ashfall does wonders to the local wildlife after they survive the initial dosage. Vvardenfell's flora and fauna are both adapted specifically to harsh conditions and regular ashfall. If the ashlanders lasted a few years past the Red Year event then they would probably be living relatively easy after the initial hardships had passed. It is certainly worth mentioning Azura as well given the interactions she is said to have had in warning the Dunmer about the event.

So for the most part their resilience and history of enduring hardships ensure their survival, almost a business as usual? Is there any sources that go further into the subject of the Red Year and life in Morrowind during?

There are likely some Ashlander clans of small regard in the Mainland - in all of the Districts of Morrowind. Mournhold, Telvannis, Velothis, Narsis and maybe even occupied Deshaan Plains.

and nope. All we get is some rumors, a mage girl from Morrowind, and some Dunmer in Windhelm wanting to go back to Mournhold.

That's all we get about our fair Morrowind.

Tis a good thing. It means we can extrapolate what we want from those events and theorize accordingly.