Moor2sea sportive training advice

boogi11

Hi all. I have signed up to do the more2sea sportive on 7th sep next year , this 112 miles and 12000ft, my biggest so far is 120 miles but only 4500ft this took 7.25 hrs. Firstly should I be able to do this, I'm 15 stone' and currently doing about 100 miles a week, It's not the distance that bothers me, it's the climbing, Can anybody offer any advice on training to achieve this. I live in the fens, so it's really flat here

Cheers