In reply to petenebo:
In the good old days, most scarpas were based on the bx last (SL and the Fitzroy) and the manta used a different last that had quite a different fit. I happily fit the bx last so dropped into most scarpa boots happily with the exception of mantas which felt too low volume for me.
With newer boots (Marmaladas, Triolet etc) I find the different lasts all fit me so I'd be happy to risk taking a punt on a pair of Scarpa online.
That said, if I was in the market for new winter boots, I'd visit a decent retailer (excuse to take trip to Snowdonia or The Lakes) and spend some time getting fitted properly. It may cost a few quid more compared to an online deal but worth the hit to save the misery of ill fitted boots.