https://wiki.project1999.com/Per-Lev...ng_Spots_45-49
The Per-Level guide is more geared towards soloers and duos/trios, but plenty of the spots on it could also support a full group.
Just looking at the level range you want, for instance, I see several undead spots in Trak's Teeth and City of Mist that should support a full group (although CoM isn't exactly "off the beaten path").
Likewise Kedge and Lower Guk could work, but may or may not qualify as "off the beaten path". Guards might work: I'm not sure if Freeport/Felwithe/Kaladim/Rivervale have enough for a full group ... but everyone in your group would have to be evil. If they aren't you
could do Grobb, but usually two people can hold down the whole zone solo so probably not enough there for a group (
maybe at 45?).
And then you have some other random outdoor zones like Wakening Lands, Ocean of Tears (Seafuries), Great Divide (Shardwurms), and ... if your group isn't on Dragon faction ... Cobalt Scar.