Because my brain is a peculiar place, the following has been going on in it:
Though Dwarves are most often associated with hills and mountains, I don't see why they couldn't be sailors and farmers. If anyone would likely be similar to them, the Dwarves make the most sense. Of course, what this means is they'd (mostly) live in an area with fjords, mountains, and colder weather. They'd also mostly be farmers rather than miners with some few going out on boats to explore and trade (and occasionally plunder).
I couldn't get rid of the idea of them being miners and crafters, but I also get the idea that they'd likely have metal ships because I just can't see them wanting to go around in boats of wood. I could also see a variety of clans each of which has a particular job: fishing, farming, sailing, mining, etc.
Also, when my brain is in more sci-fi mode, I get the notion they could be Neanderthals since, from what I've read, their bodies would not be that dissimilar.
Any thoughts on this?
Remember that 'vikings' are reallife ethnic cultural heritage, so proceed accordingly. Generally it is fine to treat the heritage for fun, entertainment, and humor. At the same time, Nordics can be surprisingly sensitive about accuracy and sensibility. Generally avoid Conan the Barbarian tropes.
(Not all Japanese are ninja, and not all Norse are berserkar.)
Regarding 'viking dwarves', the Dvergar:
• Animistic nature beings, the minds of mineral patterns, including metals, rockforms, wetland.
• When manifesting a humanlike apparition, are normal human sizes.
• It is possible for a mineral formation to project a form of human of flesh and blood.
• Highly magical, the stillness of rock is understood as a deathlike magical trance.
• Are 'fates' (nornir), associating with bad luck, but knowing any kind of magic.
• Dvergar did create the ship that belongs to Freyr.
• This 'ship' probably relates to the 'boat shaped grave marker stones', sailing magically.
• Dvergar turn to stone in direct sunlight.
In D&D.
• Make the 'Viking Dwarves' normal Human Sizes (Small, Medium, possibly very tall).
• Dwarves are one of the 'hidden folks' = nature beings projecting into the Border Ethereal.
• The 5.24 Dwarf stats are fine for an animistic being that chose to become Human.
• These retain affinity with the land. And can have children with Humans.
• Emphasize magical classes. Druid and Wizard and Artificer might be culturally typical.
• There are no spellbooks, and the Wizard 'spellbook' is actually what each Dwarf remembers.
• When a Dwarf dies, their bodies turn to stone.
• The soul of a dead Dwarf returns to the unique rock formation that it originates from.
• Resurrection spells work normally, reverting the stone to living flesh and blood.
• 'Viking Dwarves' can be sailors and merchants ... who sail at night, but at day under blankets.
• Gamewise, if taking damage from direct sunlight is unfeasible, it is narratively 'painful'.
• Sunlight is called 'the Dance of Dvalinn', a Dwarf ancestor that must avoid the sun each day.
• Mist and Fog normally obscure direct sunlight.