My first romance was Josie and while I'm sad that I didn't get the option to ask her, I headcanon that they married in Antiva, after Josie introduced Haya Adaar to her parents. 
Josie's VA said that she (Josie) would never marry without her family being present and I have to agree, she never would.
To echo myself, I really wish Cullen's family (and Trevelyan's invisible one?) could have been there, and the companions. I wouldn't do a marriage like the one in the game in real life, but it was the best the game offered *shrug*
Thanks.
Pretty much all of my Inquisitors. She was the perfect romance for me and I was hoping to finally have the perfect ending to a romance as well, but instead got the door slammed in my face. And I just know there will never be a romance that close again. 
I know somewhat how you feel. At least about Bioware probably not making another romance I like, and one I can relate to on top of it.
Cassandra is just being overly entitled, which is quite frankly the typical female behavior when it comes to marriage. They will want an expensive lavish over-the-top wedding, an expensive diamond ring of some sort, a romantic engagement that fits their entitled high standards, and the groom is just a human prop / paraphernalia.

Oh, stop your stupid generalizing already 
This is more likely to get noticed by mods than overt sexism, I know.
My main gripes over the marriage issue were:
1) Originally we were told there would be no marriage in DAI - of course technically this was true since it didn't come about until Trespasser but it was still backtracking.
2) Only female Inquisitors had the option of marriage with you actually seeing the ceremony. It may have been implied with Josephine but it didn't actually happen even in the epilogue slides. Why is it assumed that male PCs wouldn't be interested in marriage?
3) The awful joke that the writers pulled with Varric and Cassandra. Was this making fun of people who want marriage in the game? The problem for me was that it was anything but funny. For my Dorian romance it was really disappointing to have the idea that it might be possible, have Cassandra tell me to follow my heart and then rush off to find Dorian only to discover Varric holding a farewell party for him. For my Cassandra romance is was excruciatingly embarrassing to have her bring up the subject and when I seemed enthusiastic, have her awkwardly decline the offer (she wasn't Divine so what was the problem?). However, the worst one was my Solas romance where I consider the marriage "joke" was downright cruel. Vivienne and Sera were well aware that my Lavellan wasn't over him so why make Cassandra an insensitive idiot and Varric a absolute jerk for using her misery to mock Cassandra?
It didn't help my mood over the unnecessary "joke" when I discovered that some characters actually did get the option of marriage. There was nothing wrong with the marriages we did get, just the way they dealt with the issue for everyone else.
1. I don't think that kind of backtracking is a bad thing. It would be like them saying there was no armour customization, then adding it in DLC. It's just a plus.
2. That is unfortunate. I'm not sure the reasoning was that men wouldn't be interested, I think different writers were more interested in writing it than others, and it turned out in a rather unfair way because of that. Not that that makes the outcome better.
3. I agree about the joke thing. As Phoray said, I originally thought it was cool since I went over to Cullen afterwards and he did propose, but it's pretty bizarrely mean for other people. But like so many Bioware things, I just can't tell if it was something they did on purpose, or them being fandom-unaware again (not realizing the impact of what they did).
Are you saying there can't be any lesbians who are annoying and ignorant as hell?
No, there definitely are, as I've recently discovered. It's a tricky subject for representation though. Yes, in real life people can be anything, but since the only lesbian in Dragon Age is Sera, she carries the entire burden of representation. Same with Dorian.
If there were as many gay people as straight in the story, one of them being an annoying ignorant person wouldn't matter, since there would be plenty of other kinds of people doing the representing. A drop in a pond. When she's the only one though, it paints a more unfortunate picture. A similar situation arises with Dorian, because of complaints he's just another gay coming-out story (with emphasis on his relationship with his father), so he doesn't add anything groundbreaking for being the first gay companion. I don't completely agree, but I see where they're coming from.
A similar issue is that almost all of DA's bisexual characters are promiscuous rogues, because obviously being bi is deviant. Perpetuating the more negative bi stereotypes is probably not Bioware's intention, but it's still problematic. Hopefully all of these issues begin to be addressed in the next game simply by having a varied cast.