Ugh, that dreaded feeling when you realise that you won't be able to finish the game in time!
I have around 30 hours of playtime currently, arrived in Skyhold and am doing the quest with Hawke. I still haven't been to Halamshiral and have unlocked almost nothing so far. Also have to do the companion quests, too - I only started Solas' so far. Could someone help me out in telling me how I can finish the game the fastest, whilst making sure that I finished every companion quest? I'm Lv. 10, almost 11, and decided to become a Champion. I just want to be able to finish the game, so that I can play the DLC quickly; then go back to a safe state before the end of the game and do all of the side quest stuff etc.
I'm so sorry, I was in the same predicament a week ago. I had just arrived at Skyhold about four or five days ago, and after binge-playing for three days I was forced to admit either yesterday or the day before that I just wasn't going to make it in time.
Thankfully I had a less ideal Lady Lavellan x Solas playthrough where I made it near the end of the game, so I'll play the DLC with that playthrough and then backtrack to my "ideal Solavellan playthough" to play with Tresspasser on a later date.
If you don't have another playthrough with a later savepoint, it seems to me the main story is not that long if you stick only to the main story quests? (The ones that look like giant golden arrows on the maps.) Granted, you'd have to stick to the main story quests and avoid most or all exploration, side quests, and areas not connected to the mainly main story, but at least you'd get to the endgame in time...
(That is... Crestwood: avoid helping the villagers and go straight to the Warden contact. Western Approach: go straight to Hawke's and the Warden's rendezvous point, then go straight back to Skyhold to unlock the battle at Adamant Keep and Fade. Then go straight to the Winter Palace, then see the Eluvian with Morrigan, then go straight to the Arbor Wilds, then go straight back to the Eluvian with her, then trigger the final battle with Coryfish.)
It might not be ideal, but theoretically if can get you to the end-game so you can play Tresspasser.
That's all the advice I can give, because it's all I can do too. 