Basic Frostgrave is wizard, apprentice and couple of goons.
The various expantions give more options for hirelings.
Setting is the frozen ruined city of Fellstad so yes, lots of ruins, ice and snow.
Ghost Archipelago is Heritor (Big hero), Warden (less powerfull wizard than frostgrave) and some basic sailors with one or two specialists.
Setting is tropical island chain so jungle, dinosaurs and ancient tempels. Also possible small boat combat.
Terrain for both is very dense.
Also, just a heads up Frostgrave is due for a second edition next year. Mainly to bring it up to date with later releases and to tweak some of the less used spells.
If you like small scale skirmish, check out http://planetares6.blogspot.be/?m=0