Dawn of the Seeker occurs 20 years before Dragon Age Inquisition. In that movie, we see Cassandra as a young woman. Idealistically speaking, she could be 18 years old in DoTS. However, realistically speaking, she would be in her early 20s, probably 23 or 25 years old. Which means that idealistically, she will be 38 years old in DA:I and realistically, she will be 43 - 45 years old in DA:I.
Straight men of all ages usually go for young females ranging from mid 20s to their early 30s. If this is not the case, we would see a lot more cougar marriage and cougar relationships going on. Plus, 45 years old, that's my mother's age. I am not into MILFs, I know there are other straight men that are into MILFs but that just creeps me off.
All in all, Cassandra is a old butch female with more sword than sense. I prefer intelligent and ladylike women and Cassandra is neither one of those.
So its either Josephine Montilyet or no romance for me.