There are small VFDs in pre-packaged IP67 enclosures offered by some manufacturers, using an integrated external heat sink, no ventilation. Most stop at around 10HP (7.5kW), a few go a little larger (ABB goes to 30HP @ 480V in their ACS355 for example).
A few, like A-B PowerFlex, offer "fins out" versions of their chassis mount drives up to 350HP that you can install into UL type 4X enclosures, but most people consider NEMA 4X to be equivalent to IP66, not IP67, because they do have external Type 4X fans on the external heat sinks. IP67 allows for "brief submersion", which would equate to NEMA 6P and nobody is going to list a VFD that needs heat sink fans to NEMA 6P.
In my experience a TE cooler large enough to keep a VFD cool ends up costing more than the VFD itself! I generally use Compressor type A/C units, but those too are going to be IP66 at best, never IP67/NEMA 6P.
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden