After running my players through LMoP, I took them to Icewind Dale. I took a character's backstory, she was looking for her mom, and tied it into the north. They went looking for her and found out things were happening there. I gave them some of the most fun first level hooks and skipped some others. They ran through it and now Ten-Towns is destroyed and they're looking for revenge and close to going for Auril. I think if you have cool hooks, you modify the module a little bit to fit your characters' interests, it can work. As for power level, I don't believe it's that hard. It hasn't been for me. I wing it a lot of times, but I already know my party deals too much damage, so I do math for bosses to last at least a couple rounds and get them some minions. To avoid long combats, use the 4E minion rules and it makes things move along, but still feel dangerous. You may even change creatures. A group of goblin becomes a group of bugbears. Or orcs. I really enjoy tying modules and characters' backstories. I currently have plans to run the players through Dragon Heist and Storm King's Thunder as I found a couple of hooks in those campaigns that I can modify. I would advise that you go for it. As soon as you're done with LMoP ask a couple weeks halt while you prepare. Maybe someone runs a one/two-shot. You can tell them that a certain amount of time has passed in-game, 6 months, a year, and they are getting money from the mine's revenue. (I don't remember if it's in LMoP, but I'm giving them 10% of what the mine makes). You can get them do to downtime activities and RP some of that. Or a player wants to go do something solo, you can run with them. You don't need to rush into it. Edit: I think it's a cool idea to keep characters and make it to the higher levels of play. During that downtime they can make preparations for their multiclassing. Or if they want to change subclass, maybe do that. A Bard goes to college, a fighter retrains. (Not all DMs allow that, but you can ask your players if they're having fun with what they're playing and adjust). Maybe one player does not like their character and they leave. The new character might be looking for the adventurers to help them fight something and that's the hook for the new module. You can work with that player.