I was in your position after AS. Only did maths AS but got c1: 92, c2: 95, s1: 89. I thought "**** it, may as well apply." So I applied for Cambridge (lol), Warwick, Bath, Bristol and Durham. I put on my application that I was doing further maths in 1 year alongside A2 maths. I got rejected from Cambridge (surprise, surprise), rejected from Durham, offer from Warwick (A*A*A + 2 STEP), Bath (A*AA), Bristol (AAB - come from bad schools/poor family/area so a low offer). Ended up doing further maths in 1 year along with STEP, got into Warwick. Moral of the story: you can get into any of them.