My players have beaten the gobbos and are about to enter the cave next time.
The gobbos were a bit tough on them and in the end there was only the cleric and the wizard left standing. The wizard used his caracter hook artefact, a summoner collar, to summon a Djinni to take out the remaining bugbear and gobbo archers. He had to pledge a geas to the djinni in exchange for his service.
Next time dragons... Hopefully I have found a VTT to use by then.