Helldritch
Hero
To the OP.
Yes it can be done. You can make it challenging without changing the context and using creatures right out of the box. Unfortunately, you need an experienced DM to do that.
That DM will need
1) To know his players, their tactics and most of all, their magic items.
2) To have an extensive knowledge of the monsters he's going to use.
3) To have an extensive knowledge of the spells in the PHB.
4) To design adventures in such a way has to counter the 5 minutes work day. Otherwise the players will steam roll everything (or almost). 5ed is designed with multiple encounters in mind. Only one encounter isn't enough to challenge the players. You will see nova.
5) Will have to be able to adapt quickly and vary his encounters so that the players will not be able to apply a simple receipe to all encounters.
If a DM can do that, it means he has the experience needed to run a high level campaing.
Yes it can be done. You can make it challenging without changing the context and using creatures right out of the box. Unfortunately, you need an experienced DM to do that.
That DM will need
1) To know his players, their tactics and most of all, their magic items.
2) To have an extensive knowledge of the monsters he's going to use.
3) To have an extensive knowledge of the spells in the PHB.
4) To design adventures in such a way has to counter the 5 minutes work day. Otherwise the players will steam roll everything (or almost). 5ed is designed with multiple encounters in mind. Only one encounter isn't enough to challenge the players. You will see nova.
5) Will have to be able to adapt quickly and vary his encounters so that the players will not be able to apply a simple receipe to all encounters.
If a DM can do that, it means he has the experience needed to run a high level campaing.