In order to be truly Lovecraftian, the characters must be mid-twenties (the older and not-so-wiser head of the expedition may be as ancient as thirty), hold multiple PhDs, be able to build a distillery which can be switched from moonshine to desalting water with no more work than changing what you place in the pot from nothing but an arm’s-length of garden hose and two empty decanters, shoot anything from derringers to Big Bertha and speak more languages than God.
And since the women must always be nurses or librarians, we can have one who’s a librarian, has a lot of rescue animals including a cat named Lucky, and whose buggy sports an embroidered fish-with-feet (we’re following the “rule of cool”: it doesn’t matter if it’s not logical so long as it’s cool).