Hey Track, hope you're having fun with this, you use the fog to prevent the archers from moving forward, given that fog requires concentration you can choose at what time it dissipates. If you stand where I am in the images, you have enough movement to move to the edge of the grease shoot and move back, which is out of range of the goblin archers.
Also, concentrate your shots on a single goblin and take them out one at a time, which usually means they never get a shot off at you, but even if they do, they are unlikely to do you enough damage to kill you and you can always use your cleric to heal. Another tip is don't forget to cast Bless before you go into the battle
