I'm having the same issue and it's really frustrating. I'm about 35 hours into the game. As far as I've noticed, Mother Giselle hasn't left the gardens since I got Skyhold. I've completed Dorian's Venatori quest and exhausted all of his dialogue. He flirts with me when I try to talk to him, but other than that, there's nothing. I definitely don't have the patience to restart the game completely.
Luckily, I do have a bunch of side stuff--like completing Astrariums, killing dragons, and fetching books for Vivienne--that I can use to distract myself for a while. I really hope there's a patch soon, because otherwise this playthrough feels wasted. Romances and roleplaying are the main ways I differentiate my playthroughs and this Inquisitor only has eyes for Dorian.