Discussion: Transitioning between campaigns

I am curious, as to how my DM colleagues handling transitioning from one campaign to another.

We are currently 2/3 of the way through Tyranny of Dragons so I am beginning to think about what to do when we're done with this adventure. During the campaign, my players have all switched character as least once. Some of the current characters are incredible well crafted and we have together generated an amazing amount of background lore on these characters.

Personally, I feel there is a certain amount of "danger" in reusing a character as the is a huge risk of being disappointed with the new reincarnation when one envitably compares with the previous incarnation. But I may of course be mistaken. 

 I don't want to ban my players from a reincarnating a character concept they have fun with, but I want to hear what other DMs might have of opinions and experience with rerolling a character and essentially reusing this character in another campaign? 

In relation to this, I am considering several official adventures for a new campaign. 

Once, we're done with ToD, the characters will likely be around level 17. Advancing beyond this level is ... difficult as there isn't a lot of official material, and I don't have the time or energy to make my own. So, once ToD is done, we'll start on something new. 

I'd like to start a new campaign based on e.g. Baldur's Gate: Descend into Avernus, but I also want to do Curse of Strahd. It would also be fun to something entirely different and do Wild Beyond the Witchlight. Waterdeep: Dragon Heist is also in the runnings. 

The problem is, that all of these excellent adventures all start at level 1, and my group thrives best with long-running campaigns and characters that can develop beyond level 8-10. So, I have been thinking about merging two or more of these adventures into one long-running campaign. For context, I should add, that we typically play once every two weeks, typically for a 5-6 hour session. 

So, what to do? I am a bit conflicted on how I best approach this conundrum. 

Well, one published campaign, Vecna, Eve of Ruin, goes 10-20, so you can drop that in on the end of a campaign to level 10.

I can respect that you don't have time to make your own content, and can acknowledge that going beyond level 17 is hard, but I, personally, find it very gratifying to make my own stuff. Just putting it out there that it can feel very good.

Quote from WolfeCriedPup >>

Just putting it out there that it can feel very good.

 Oh, I completely agree, I just don't have that creative spark any more. :(