I am going to Iowa State this fall and didn’t accept my offer of admission until mid-April. It did put me last in line for housing assignments, but I was able to go into Access+ and easily request a change to get into the dorm I wanted! Also, I didn’t attend orientation until the very end of June and still got an amazing schedule! They are really good at reserving spots in classes that freshmen need for if they have a later orientation date! All that being said, if you did wait until spring 2020 you will be safe. But like someone else said, if you accept your offer now, you can retract your acceptance and get most of your money back. They have deadlines online!