Updated: Dec 9, 2019
Stating the obvious, this will be a long ride home. Bianchi is located in Treviglio, near Milan in Northern Italy. Whatever route I choose is going to be hard. If I choose a straight line north, then I will have to ride over the Alps. To avoid the mountains, I would have to go west into Southern France and then north. That adds around 200km to a trip that was already 1800km. I am not keen on making it even longer. Some searching around the web quickly showed me that there is already a bike route from Milan to London, EuroVelo 5. This follows the historic path taken by pilgrims from Canterbury in Kent to Rome. EuroVelo 5 travels through Italy, Switzerland, France, Germany, Luxembourg, Belgium, back to France again and then England via the cross channel ferry.
I found a book ( Good Vibrations - Crossing Europe On a Bike called Reggie ) by Andrew P Sykes who had ridden from Canterbury to southern Italy using the EuroVelo 5 route. The book was informative and captured both the ups and downs of riding alone. But it was written about a very different type of ride than I am planning, on a touring bike with fully loaded panniers. I have no intention of camping, it's just not my thing at all.
A bit further searching found the website www.biroto.eu which had a downloadable Garmin file of the entire route, cutting out hours of plotting over maps. It looks like I will be going the Alps then. The route profile goes from one huge climb in Switzerland to seemingly flat all the way afterwards, although this is clearly meant to lure me in with the idea that it will get easier.