i'm gonna be completely real here: i did 4 a levels, two epqs, alongside various dance and drama qualifications so it's completely doable and i have loads of free time (+ an oxford offer). my main tip is just do the epq stuff as early as possible because then it's fine to keep up with? i ended up redoing my first one because i got a B but i have full marks on the second one so i'd suggest provide supporting documents, at length, and don't be afraid to lie on your epq. go forth and conquer
edit:
my a levels are english lit, classical civ, history, and drama & my epqs were on psychology & ancient history respectively - i did most of my interview stuff over summer so i had like 20 drafts of my personal statement, but i also did a lot of extracurricular stuff (related to my degree subject, not just generic) & entrance exam & interview practice, so i want to tell you it's definitely doable, it's only really hell during the actual exam period due to the placement of exams. i also will add that i have had a lot of free time so don't let that put you off (you can also drop an a level or an epq later! :3) and also i have appalling time management so that wasn't much of a problem either (if your epq time management sucks, LIE.)