In reply to jbpilon:
A slight modification to your programme that you might consider:
1. Breithorn W > Cabane d'Ayas.
2. Pollux > Castor > QS. Pollux could equally be tagged on to day 1 but it makes more sense to do it on day 2 when you've got loads of time. It would be a shame to miss it out.
3. Naso del Liskamm > Mantova/Gnifetti.
4. Signalkuppe/Margherita via as many of the little Monte Rosa tops as you feel you can do.
5. Zumstein > descent to Gressonney doing the other tops you didn't do yesterday.
The advantages of planning to go to Mantova or Gnifetti before Margherita are:
a. They're lower and give you another day of acclimatisation. I've stayed at Margherita a number of times - and only slept once!
b. The long rising traverse of the Naso is reasonably exposed. When it's dry (ice rather than snow) it can be quite a formidable section. That whole section can be avoided if necessary in these conditions by descending to Stafal then walking up to Mantova/Gnifetti using uplift as you need/want. Obviously you can do this if you get bad weather for that day, too.
It's a fabulous trip and justifiably popular. Booking huts therefore is essential.