Specifically in the Cirque du Cheval, Cirque des Fonts and Vallee des Sales!
Is it often in nick, does it require ski/snowshoe access and is it possible to base ourselves in a hotel in the valley, or will we need to camp or stay in a winter room? (looks like only the Grenairon has one - annoyingly, not the Refuge des Fonts). Will we need a 4x4?
Most importantly, is there much in the area at or below WI4, or is it all really serious stuff?
In reply to jhw:
I was living in salvagny (looking into the vallon des sales from our lounge window) for 5 years. So I've done a fair bit of the ice climbing there.
Conditions in the valley bases (e.g. approx 800m altitude) are fickle, and best in late Jan-mid Feb; however the vallon des sales / les fonts / fer a cheval are pretty reliable for forming ice from early Jan to mid March...these areas are relatively high e.g. 1300m cliff base; however the fer a cheval is very tricky to climb in, it is often hard to get safe conditions as it has serious avalanche danger due to its aspect and nature of cliffs above the ice. The climbs in the cirque are mostly super serious...
As ever the need for snowshoes / skis will always depend on conditions, but yes mostly it is useful to have them. A lot of the time I'd say you could get away without them, but often your approach and descent will be made a lot pleasanter with!
You don't need a 4x4...just winter tyres and snow chains in case.
You can find places to stay in the valley in salvagny and sixt e.g hotels like Le Petit Tetras (find it via google).
Re seriousness, it is not very frequented and so the climbs in the areas you mentioned generally feel (and often are!) quite remote and serious. Of all the areas the main wall of the Vallon de Sales is most amenable (and reliable) with several climbs in the WI4-5 category and straightforward approach. Generally you'd have more options and be more likely to get a better trip if you are climbing WI5 or above. However, if you're there during cold conditions in jan-feb then you can also get a lot more in the WI3-4 category forming in the valley bottom.
If you'd like to see some photos for info I have a couple of sets on my flickr account http://www.flickr.com/photos/alpineelephant/ (ignore the photos of my new pet cat!)
I guess you may have seen the guide to the area: Cascades de Glace du Mont Blanc au Leman, Volume 2, JM Editions. The Lac de Montriond area is also superb and not far to drive.
Hope this is useful,