I'm seriously considering buying one of the Boardman Performance Hybrid bikes, but i'm a short arse & the smallest frame has a seattube length of 45cm.
What does this equate to in the real world and any idea of the standover height?

Really want one of these but i think i'm too short. (5'2")

I am thinking about getting one and at 5'7" would be going for the small so i think you may struggle. Prob best to try one out.

I'm 5'2" and have just ordered myself a small Team Pro Ltd Hybrid. I tried the standover in store and there was plenty of 'clearance'

My inside leg is 28 inches and there was a good inch or so between me and the toptube (although I don't have any 'danglies' to worry about! 😉 )