They won, in the sense that they are the largest party in every province. But of course, in the Netherlands we have a multi-party system, so being the largest "merely" means that they got between 13% and 33% in every province, and all other parties got less than they did in every province.
In most cases, it'll be possible to cut them out by forming an establishment coalition. In the First Chamber (Dutch Senate), they will have 16 out of 75 seats. Given that other right-wing parties also have a few seats, this is almost enough to ensure that the governing coalition is struck lame... but not quite. The left-wing Labour/Green bloc has precisely enough votes to still prop up the coalition with tacit support. In return for this, they'll demand more left-wing policies.
If the Farmer and Burgher Movement can form right-wing coalitions in some provinces and lead a vocal opposition elsewhere, there may be another land-slide when the next elections take place for the Second Chamber (Dutch House of Representatives)... in 2025.
Until then, the establishment will do anything to prevent early elections, because if the government falls now, they'll lose spectacularly. The hope of the government, now, is that the opposition will lose momentum, so that come 2025, "the shne will have worn off", and the people will vote for the familiar establishment again. Going by past experience, this is a sadly realistic prospect. (But on the other hand, Premier Rutte has been in power for thirteen years now, and people are getting tired of his shit...)