I'd like to emphasize here that it is just pure speculation that vampire would die at some point without feeding. This is just my feeling, but it doesn't make sense to me, how someone who manages to survive for 50 years without any food, could die from starvation.
There is no doubt that it starts as a disease, the thing is what happens next.
Grey prince seems to be an exception, a divine intervention from Mara perhaps... there is no other example. Also the ability to reproduce doesn't have to contradict that they are undead.
I think it is gameplay mechanics, there are two reasons why I think so: 1. Vampires are classified as "NPC" other undead are classified as "creatures". 2. There is this passage from Vampires of Vvardenfell: ...The "ash vampire" of Ashlander legend is not undead. Sorceries and blessings affecting the undead reportedly have no effect on these creatures. I know that it doesn't directly say that magic against undead works on vampires, but why mention that it doesn't work against ash vampires then?
There is no doubt that it starts as a disease, the thing is what happens next.
Grey prince seems to be an exception, a divine intervention from Mara perhaps... there is no other example. Also the ability to reproduce doesn't have to contradict that they are undead.
I think it is gameplay mechanics, there are two reasons why I think so: 1. Vampires are classified as "NPC" other undead are classified as "creatures". 2. There is this passage from Vampires of Vvardenfell: ...The "ash vampire" of Ashlander legend is not undead. Sorceries and blessings affecting the undead reportedly have no effect on these creatures. I know that it doesn't directly say that magic against undead works on vampires, but why mention that it doesn't work against ash vampires then?
It isn't speculation so much as we simply don't know how long it would take to figure out, if it all possible. I mean, maybe they do and maybe they don't. We don't know either way, but it is something to account for. And yet even before I quoted Hassildor, people were speaking as if they were suggesting not eating didn't do anything to the bother that much. Or that's the impression I got. Of course they noted some would go mad but... The longest non-feeding time frame for a vampire from what I can tell is more than 50 years, which goes to the Count's wife. The next is an unstated time for the Prince's father, who suggested he was "fine." Some on here have stated ~20 years, which wouldn't be bad considering the time between Lord Lov told the truth and the time we'd meet him later/the possible age of the Prince/time we (if doing the vampire curse) cure the Count's wife. And even if it was slightly more than 20 years, I would verily doubt it was more than 20 years. So, and to reply to Werewolves&Vampires mention of it, too, with that in mind, his time compared to Rona's is quite substantial in the difference. We also don't know how Rona acted pre-coma. Perhaps she went a little wild. And yes, it would also be determined by age. Lord Lov was over two hundred years old, while Rona would be maybe around 90 or 100, so he may be able to hold it off longer. But I would assume if forcefully kept from feeding (because he wanted to), then he would end up in a coma, too.
At this point, I think it'd be better to say we don't know how long it'd take them to die versus they don't die from not feeding. It may not seem to be logical, but in fact it is nothing more than logical when you have enhanced abilities like a vampire to survive 50 years and then some by not eating. And then to add in a coma, which would lengthen it. Yes, it is true we don't know whether or not they would do, but I'd prefer to say we don't know how long it would take because there has to be a point at which their body simply stops. We already know the stages they go through if they don't feed, with minimal outliers. And reiterating, age is a factor. And if they can grow weak to the point their own body cannot sustain itself, then... what is next? And sure, I won't be the last to say this is mostly speculation and conjecturing. But I feel I have enough evidence to at least come this far to support my hypotheses.
As for the disease part... No other undead can spread the disease. Zombies aren't even like the modern mythological creature we make them out to be, the whole zombie-disease spreading. But no other undead starts off as a disease, behaves, and they certainly cannot spread it. This lends itself to the idea it's a disease/curse/virus. And vampires are in no manner like other undead in any capacity aside from the either literal or metaphorical death they encounter after 3 days. Their behaviour simply doesn't fit the profile. Yes, this is TES. Their rules. They want them undead, sure, lol. But meh...
Vampires feed, unlike other undead. They also spread the disease, unlike other undead, whom of which don't have anything to spread. Other undead also are not typically seen in a civil environment with high cognitive functions, aside from Lich, which are an exception. There's really a lot of differences I could list but sadly I am too tired. =(
It doesn't have to contradict they're undead, the fact they can have children. You're right. But given all the other examples of undead, and the precedent they set? It kinda does contract, along with all the other differences. The only similarity between the rest of the undead and vampires is that vampires are believed by some to actually die. But given tons of other evidence, and the possibility it could be metaphorical, then that means there are no similarities. Well, I take that back - Lich and vampires have extended lives. Idk about Zombies and skeletons, how long they could perform their actions without requiring routine attention.