36 hrs (6 days) 1500 km
  1. depart PDX towards Milan
  2. red-eye overnight, land, collect bike
  3. Milan to La Spezia 4h42m 245km
  4. La Spezia south to Piombino and ferry to Bastia France 4h riding then (1h20m + 3h31m)
  5. Corsica to Bonifacio
  6. Sardenia to Cagliari
  7. possibly need 2 or 3 more days
  8. Ferry to Sicily Porto di Trapani (near Palermo)
  9. Sicily 1
  10. Sicily 2
  11. Sicily 3
  12. southern Italy
  13. to Brindisi
  14. ferry to Corfu, Greece
  15. Corfu 1
  16. Corfu 2
  17. ferry to Ladochori, Greece
  18. Greece 1
  19. Greece 2
  20. Greece 3
  21. Greece 4
  22. Athens back to Milan via Skopje and Kotor (27 hrs, 2313 km) 5 days
  23. buffer day back in Milan
  24. fly home
Approx 4 weeks.

Examples from AMT, etc


beautiful-balkans-adventure
adriatic-riviera-tour
intriguing-southeast-europe
romania-to-istanbul-adventure
balkans-and-adriatic-explorer
greece-tour
south-of-rome-sicily-tour
tuscany-sardinia-corsica-tour
sicily-tour
italia-espresso-tour-of-tuscany
czech-hungary-tour
grand-european-tour

Sardenia and Corsica


sardinia-corsica-riders-heaven





Based on the AMT tour, I came up with this x day North to South transition

Sicily



Italy's toe


This route takes about 3 days exploring the "toe of Italy" ending at Napoli.

Straw man schedule


Elapsed 33 days. Dave says
I’m pretty sure I’ll book a flight that will bring into Europe 2-3 days before we meet up on the 28th.  
I’ll do some solo sightseeing until we meet up.  I can rent a little car for 30-40 bucks a day.  
I’ll be over the jet lag when I meet up with you and ready to go. 
I’ll fly home May 17 +/- a day.

My plan is to rent a small car (VW Polo) and visit Lucerne, Matterhorn, Geneva and Lyon.  
Plan to take train from Geneva to Milan on the 28th - stay overnight in Milan and meet up with you on 29th. 

Dave suggests:
1. Glacier National Park, Montana
2. Yellowstone National Park, Wyoming
3. Grand Teton National Park, Wyoming
4. Jackson Hole, Wyoming
5. Bryce Canyon National Park, Utah
6. Zion National Park, Utah
7. Belly of the Dragon, Utah
8. Lake Powell, Arizona
9. Horseshoe Bend, Arizona
10. Grand Canyon National Park, Arizona

Some pieces of Greece

sites to see LOT Polish airlines flight changed from
   Thu May 23  Fly MXP  7:25am-2h10m->WAW 9:35am  LOT 322 2h40m layover in Warsaw
                   WAW 12:15pm-10h5m->ORD 3:20pm  LO 1   UNKRC2  1 172,52 EUR  $1,344.53
to
   Thu May 23  Fly MXP 10:30am-2h10m->WAW 12:40pm  LOT 318 4h layover in Warsaw
                   WAW 16:40pm-10h5m->ORD 19:45pm  LO 3   UNKRC2  1 172,52 EUR  $1,344.53
Shifted 3hrs later, layover increased 1h20m, arrival delayed 4h25m *uggh!* No chance to see Chicago in the evening after our arrival. And it's going to feel like arriving ~2am.

Ferry Options