After the great European Piano Parties in the past years, the idea came up to have the next one in Germany, especially on the Rhine.
I looked a bit up, and it turned out that finding a location is challenging.

Several ideas came to mind.
1) Piano party on a ship on the Rhine, with a grand piano.
2) Piano party in a location on the Rhine; preferably close to the Loreley; including a ship trip.
3) Piano party somewhere else.
Option 1 would be the most challenging to find. There are not many public ships for passengers on the Rhine which have grand pianos.

Another thing to consider: When?
Two options: July or early fall, namely September.
Advantage of July: Better weather. The weather in September in Germany can be a lottery game. We could be lucky and have temperatures in the low 20s (centigrade); but we could also have temperatures in the one-digit area.
Advantage of September: Possibly more options for finding a location, and possibly better prices.

I contacted some venues which would fulfill categories 1 or 2 above, and they are already booked out on the first July weekend 2018, and have told me that booking one year in advance is sometimes necessary.

So: I am asking this especially the EPP veterans. Which is your preferred option?
Especially: Which is your preferred time?

I consider option 3 (Piano party somewhere else) a last resort, in case I can't find a location on the Rhine or close to it.

I love long range planning!!!

Personally, I'm ok with early fall.
I'd rather deal with cooler weather - and yes, even rain - and put on a sweater than have to deal with some of the extreme heat we've had the past few summers.

Plus, again speaking just for myself - I am pretty sure that I will have commitments with family in July.

The experience on the Rhine could be really great - but I am equally supportive of holding the party in a restaurant, hotel or bar of some sort that has a piano.

If need be - -- maybe there's a place that has sufficient space and we can bring a piano in? If we have 10 pianists it wouldn't be that much per person - just a thought.

I have not yet been to a piano party, but this post got me rather interested. I would prefer option 2), with or without boat trip. Playing the piano on a boat on the move (option 1) might be somewhat uncomfortable. If it should be September, then right at the beginning of the month since I got many appointments from September 12th onwards. Furthermore, the weather should not yet be a problem then.

@Pianist 685 - It would be great to meet another European Pianist !

Well, Belgium - Germany, will it ever be closer...? If nothing comes up, I might join.

Our very first one was in Brussels!
Where in Belgium are you? You could host 2019!

It would be lovely to meet you, in either country!

20 km from Brussels :-), but I guess I wasn't into piano playing back then. btw Belgium is only 300 km from top to bottom or from right to left :-) +-200 miles

My husband and I have visited Belgium several times- and driven through it too
The Brussels party was in July 2013, looks like you may have started a few months after that.

I love the idea of a European Piano Party in Germany in the Rhine area. I love it there! I just returned from a visit there, and it was lovely. I would prefer September over July because I prefer the cooler fall weather, and I think it could be less crowded and easier to find a venue. However, I am happy with either time. Option two is my choice. There are several nice towns between Rudesheim and Boppard that have nice hotels, but I do not know of one with a piano. The River cruise boats stop at all of the towns. I really like the idea of a boat cruise on one of the days.

OK, I am already excited about this!

Quick update: I am now looking for a location on the Rhine with a grand piano; not on a ship; for September 2018. This seems to be the most popular option.
The search is not easy. I will inform you if I find a location. It might be a hotel, or an academy; or something else. The instrument has to be a grand piano.

We are now looking into two options for Germany 2018: A music academy in Sankt Goar, and Nürnberg, with a location to be determined.

Since these European Piano Parties originate from the Adult Beginners Forum, I have started a new thread there.
http://forum.pianoworld.com/ubbthreads.php/topics/2683178/european-piano-party-2018-in-germany.html

Admins: This thread here can now be closed, so the discussion is kept in one place. Thanks.