Windowsill plants

[Pilif]

I noticed today I've got a windowsill (outside) that hasn't got any plants on it, and since the window itself faces a rather dull/ugly wall something green wouldn't do it any bad I think. The problem is the windowsill doesn't really have the conditions to grow cacti; so I'm wondering if someone knows of any succulents (or something else that's perennial/not dying back in winter) that can grow in the following conditions:

West-faced windowsill, 2hours of sun/day max;
outside, sheltered from rain;
winter temps may go down to -10°C (-15°C in extremis).

I don't have high hopes, but if someone has any ideas please share them

EDIT: I'm having plans to grow shade-surviving cacti (gymnocalycium etc.) on the inside with the aid of a growing lamp; but those are long-term plans.

[alkravi]

You may want to grow Aztekiums, Obregonia denegrii, Lophophora, G. ragonesii and other dark skinned, Blossfeldia, it will be perfect for grafts on Pereskiopsis also.

PS I'm not advising to keep them there during winter, г need to maintain temperatures at least >0C. The first three and Blossfeldia will probably be OK at -5.

[fixpix]

Why not some sedums/sempervivums?
Depends how care-free you'd like these plants to be.
You could create a nice windowbox with different kinds/colors, rosettes, trailing, hanging... and they stay cool even in winter.
Calin