Good luck! I know you'll have a blast. Try and post about your experience tomorrow!
Man, that was so much fun. The first part of our evening was moving towards the conclusion of my 5 year 4e campaign. The last session will be the party facing off against Bel-Shalor in the shattered ruins of Flamekeep. Then we did an hour of 5e and Phandelver. It certainly proved that you can get a lot done in an hour.
The first 40 minutes was setting the scenario, people explaining their characters and some rollplay on the road. Then they went off to the triboar trail. The rogue went a little ahead to scope out the situation. He was staying stealthy and in the undergrowth at the side of the road, but as he turned the corner where the ambush was he rolled a critical failure on his stealth and got caught up on some brambles. He saw the dead horses and went back to inform the rest of the party. He then went back with the monk not far behind. The rest of the group got onto defensive positions on the wagon. Because of the previous failure on stealth the goblins were now highly alert (advantage on perception) and saw the rogue sneaking through the bushes towards the horses. The two goblin archers stood up and shot at him. Thwack, thwack. Two arrows embedded and he was down. The monk decided to throw a dart at an archer but missed. The two goblin swordsmen then emerged from the bushes, came over and gave him the smackdown. That was two players out.
While this was happening, the characters around the corner were hearing the sounds of swords and shooting, so the second rogue decided to move up and peek around the corner. When he saw the tableau before him he shot a goblins swordsman through the face, killing him, and then retreated back to the wagon and cover.
The archers moved through the brush on the other side of the road as the swordman drew his bow and moved to the corner. All three of them went to shoot at the remainder of the party, but all the characters had readied actions. Spells and arrows flew at the two archers who both went down. One of the players then demanded that the swordman drop his weapon or die (intimidate check). The goblin did so and surrendered. They then ran around to try and save the two downed party members. The rogue had stablised already, but the monk was on the edge of death (2 failures, 1 success). He was healed in quick order.
By this time it was 1/2 an hour past our normal finish time. We were all having so much fun that nobody had noticed.
This was so easy to run and so easy to play. There was a real tension and the combat happened so quickly that even the people who were unconscious didn't get bored because their turns came around so quickly for the death saves.
I won't be back to this for three weeks (next week I'm working at night, and the week following will be the final encounter for my 4e campaign), but if all of 5e is this fun and easy I won't be missing any of the previous editions.