Around 40 minutes to beat this free DLC on Normal. Its only around 40 minutes and 4 missions. I spent some additional time since I started the game over, expecting the side missions to show up on the map. By the time they did it was several main missions in and I realised I had to unlock more of the map to get the rest of these side missions. Having beat the game years ago I went back to an old save where I had the full world map unlocked, and this allowed me to do all the missions without any interruptions. Its reccomended you finish the main campaign or do this late game to avoid interruptions. I also have an Expert mode run in early progress that I may get back to eventually.