The Big European Vacation, Germany-France-Netherlands

The Germany-Paris sleeper train was discontinued last December. Probably not a great idea anyway.
Where in Germany do you want to go, and what ages are the family?
Conventions in the summer months are not that big a problem. They usually go Sept to May.

You'll get a big dropoff charge if you rent a van in one country and leave it in another. But not if you leave it in a different city in the country where you rented it. So maybe worthwhile to return to Germany for van dropoff purposes and plan your flights accordingly.

Rail vs. van depends on how much flexibility you want (argues for van), and how much six train fares will cost vs. the van rental (likely argues for van but may depend on ages and how far ahead you buy tickets -- but see the flexibility tradeoff). Also whether you want to visit mainly big cities (train is easier) or also countryside (van easier).

Auto Europe can give you a good idea of van rental cost, and may be the best way to rent one, but shop around. Their advantage is a US contact, their disadvantage is you're not dealing directly with the rental company (but I've never had a problem with that). You pay them and get a voucher to present at the rental location. You can change your plans with them and get price adjustments accordingly.

For trains, see this link on the RS website, and this website to look up schedules and fares (but not to book tickets except for Germany). Note that schedules and fares for June 2016 aren't posted yet, and won't be till late this year, but major changes are unlikely so you can use the site for planning. I'd agree with the previous poster that overnight trains aren't a good option, even if available -- too hard to sleep.

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Keep in mind extra insurance charges, filling the tank to return the car, etc., when you are calculating price comparisons. A two-week van rental can go for about $1500.

I'd keep a van rental as an option for Germany, but it would be worse than useless in Paris and Amsterdom. So ditch it in Germany. Paris is only 4 hours from cities in western Germany by train.
But there are lots of budget options, especially using Laender tickets for a family of 6 to get around in Germany. Just depends on where you want to go and what you want to do.

The best fares on reserved train tickets go on sale 3 - 4 months in advance of the travel date, so next March will be a good time to think about confirming those big-city connection plans. (Or flights are for sale earlier at www.skyscanner.com.)

Jeff,

It would help to have more specific information on your proposed trip, for example which places you'll be visiting in Germany. I doubt that a Van would be a good option, for the reasons previously mentioned. Trains and other public transit are excellent in Europe, and that will be much faster than by road and a much more efficient use of travel time. The high speed trains travel at up to 300 kmH, so no vehicle can (legally) match that.

Hi,

There are two night train lines which might interest you: Munich to Amsterdam and Offenburg to Amsterdam. Both are CNL routes indicating start to terminus. These two routes might apply if you want to change your itinerary a bit, say Munich to Amsterdam by night train, then Paris by train. Where are landing in Germany? True that night trains from Germany to Paris have been abolished. The Frankfurt-Paris Est on the ICE is direct, arriving at 1650 hrs.