The description of the environment appears to negate the possibility of hiding in this fashion. It's a road with an embankment on either side. That's wide open - nothing to hide behind. The trees are up on the embankment.
Which is why I said it depends on if the DM thinks there is enough cover for it. Still, the description of the encounter does state that "the woods press close to the trail here, with a steep embankment and dense thickets on either side." To me that seems like it's at least worth asking the DM if stealth alongside the woods is an option. If the player has it in his head that there's plenty of places to hide (places like the goblins found) and sneak around, the DM should be able to quickly confirm or clarify it. That sort of Player/DM communication is actually pretty important to establish.