They'll be long travel days but it is entirely possible use bahn.de as a planner
Berlin - Budapest
- Berlin Hbf - Budapest-Nyugati 09:01 - 20:28 free 1st class reservation (via Prague, quite scenic) OR
- Berlin Hbf - Wien Hbf 10:04 - 17:47 free 1st class reservation
- Wien Hbf - Budapest-Keleti 18:42 - 21:19 free 1st class reservation
Budapest - Paris
- Budapest-Keleti - München Hbf 07:40 - 14:32 free 1st class reservation
- München Hbf - Stuttgart Hbf 15:28 - 17:45 free 1st class reservation
- Stuttgart Hbf - Paris-Est 18:52 - 22:05 30€ 1st class reservation
Milan - Naples plenty of direct trains (15€ seat reservation). The full timetable isn't available yet
It was a good idea to buy 1st class passes as the seats are quite comfy and it will be less crowded than 2nd
Paris - Como
The direct TGV into Switzerland has a 70€ 1st class fee so better to avoid it.
- Paris Gare de Lyon - Mulhouse 07:22 - 10:03 10€ (same TGV that goes to Zurich but you leave at the border)
- Mulhouse - Basel SBB 10:16 - 10:40
- Basel SBB - Zürich HB 11:06 - 12:00
From Zurich there are 2 trains per hour to Como. No reservations in Switzerland. Change in Lugano as the direct Zurich - Como EC has a 13€ fee for 1 km in Italy... (5 min quicker than the direct train)
Brillant thank you so much