Hi Helena,
Sounds like you've been on some fantasic journeys! and I'm sure our visitors to Europe would love to see a Trip Report on your Rome trip:
http://www.destination360.com/forum/italy/
Ok on to your question I personally have not cycled Patagonia but people do it all the time and you have the time so why not!
Yan and Ben did a primarly Chilean bike trip in 04 and documented their amazing journey with fantastic notes at
http://www.waterdropfilms.com/travel...004/diary.html. I think their notes section you might find useful since the climate and terrain is very similar.
These folks have paid bike trips that will give you some good ideas of the segments.
http://www.interpatagonia.com/turism...ura/mtb_i.html
Here's a huge collection of bike journeys in the Americas that you can pick through
http://www.swb.de/personal/elch/e_amerika.html#AMERIKA
You may find by piecing together a few of these adventures together you'll come up with our own unique adventure to share with us. If your looking for a tour group then we can certainly help out but I get the feeling you don't want to be tied down to a group.
Let me know if there's anything we can do.
Cheers,
Dan