Thanks mcours2006 and kuroba! I think the gravel bike will be! I will be shopping this weekend, going to my LBS especially to measure it and see how they fit as I am 160cm tall.
I like the Mango bikes, thanks for the link kuroba. I didn't know them.

In London, during summer the weather is great but during winter is very cold and wet, yes.

I will probably check a road bike and add wider tires as I really don't like the road tires, which are thin. :-)