I've had very similar problems over the years as well, train travel with a bike on the continent is an absolute pain. I must admit I've all but given up, long distance travel is just too fraught on public transport.
Having said all that and looking at a map a thought does occur. I presume you'll be traveling across to the Hook of holland? Why not then cycle into Rotterdam or failing that, cycle all the way to the German border if time allows? Then once in Germany it's generally not too bad. All of the long distance ICE trains have some space for bikes as long as there booked in advance. Long distance IC trains have even more space for bikes and are not much slower. Local trains are even easier but much slower, booking in advance on local trains is not needed you just need buy a bike ticket. Up here in Niedersachsen it's €6 for the entire day, no matter how far you travel. I've travelled long distance on ICE trains with a fully loaded bike a few times now and it's not too stressful at all. In typical German fashion the trains are mostly quite organised, The platforms will have a sign board showing the layout of the IC and ICE trains that stop there. So it's a simple matter to work out where exactly the bike carrying part of the carriage will stop. The only thing to be aware of, is you will need to hang up the bike by the front wheel, which can be a bit of a faff. We are having a lot of engineering work at the moment which is generally causing some major chaos on the trains, but it should be possible as long as you're happy to have an adventure.
