Now before you cry and swear at Square Enix, they did specifically mentioned that the main story up till patch 2.55 needs to be done before getting into Ishgard and all that new stuff. There has been several threads about this and none too happy about it though i would strongly advice you to be patient and ride through the story and progress till the Expansion as it is the way it is intended to be played. It's a story based MMO after all. There will be a few annoying moments where you are required to complete certain Guildhest quests, those i will agree that SE should streamline to improve the pace and ease of getting through the long list of quests but none takes too long to be done as i find that queueing in Duty Finder to get a group going doesn't take more than 10 minutes to form these days. If you can afford to play for more than 5 hours a day, it shouldn't take more than 3 days to get to Heavensward. I took my time and roughly reached Ishgard in a week playing 1.5 hours a day.