Almost exactly a year ago my wife and I visited Europe (Germany and Italy) for 18 days with our then 3 month old daughter.
Honestly our DD did WAY BETTER than us in terms of jet lag! She napped on the plane ride over multiple times, but never got that good "I am sleeping for the night" type of sleep. Then when we arrived we carried her around in either a Bjorn or a Sling letting her sleep when she needed (the sling was especially good at letting her sleep while we carried her around). We just made an effort to not put her in her crib until about 6 or 7ish the night we arrived, and she was plenty tired from airplane trip that she fell asleep pretty easily. She slept her ~12 hours and woke up the next day pretty much "on" the timezone we were at. It took my wife and I another day or 2 to get fully acclimated, but our daughter had no problem at all.
My "theory" is that with all of the naps, it is actually a LOT easier to travel with a child that is 3-4 months old than if they were older. Just be aware of when your baby needs to take a nap, be prepared to go a bit slower and you should have a wonderful trip.