End of Campaign Conundrum

The new adventure path prop…

As a Games Master the adventure path that I have run for my current players in Pathfinder is the first time I have ever run a campaign in a D&D fashioned environment that has had the players reach so many levels.  Most prior campaigns that I have run have been home grown campaigns that ranged from first level and finished around eighth or ninth level with the possibility of further play that never came about.  Other systems are different, and I have played a lot of other systems, where I have run campaigns that spanned years and up to the highest level of power.

I am now faced with a conundrum as the adventure path slowly comes to a close.  The players are heavily into their characters and want to take them “all the way” to twentieth level but the adventure path caters only up until late seventeenth level.  The adventure path has a whole range of options of what to do once the adventure path finishes but I personally do not like them much.  The players have some ideas on what they want to do past the end of the module (for example, the alchemist wants to return to Smuggler’s Shiv and take it over, turning it into an adventuring theme park of sorts!) but they also do not yet know what the end of the module has in store for them.

The next adventure path in waiting!

Complicate that scenario with the fact that all the players have rolled up new first level characters (and are excited to play) for the Skull and Shackles adventure path.  I have been patiently been building a model boat to aid in bringing this game alive and most of us are really keen to get into the shenanigans of a full blown piratical adventure.  I have stated to the players on several occasions that I wanted to start the new adventure path asap after the serpent skull one finishes but am I doing the right thing?

There is one other option I had been considering also, but it comes from a place of ease on my part.  I had considered running a final “mega-dungeon bash” through Savith’s crypt as a finale that would take the players into the heart of her tomb, give them some great treasure and the ability to come out at the end as twentieth level characters.  This is from the perspective that it is pretty easy to design a dungeon bash for a group and would be the least time intensive on myself as far as design goes.

So, do I:

1. Wait until the current adventure path completes, find out where the characters are at and as a reward for their loyalty and playing design the last few adventures around their wants and desires?  This option would likely take a lot of design time but be a real boost for the players who at times have felt railroaded in the current adventure path.
2. Begin to design now using one of the ideas in the adventure path designed to take the characters on from the end of the adventure?  This option would largely be an extension of the main plot and may feel a little tired for the players when they hit the end of the final module and then have to deal with further problems that arise.
3. Start the Skull & Shackles adventure path immediately and put the last campaign characters out to pasture for a while so I can design some intricate stuff around what they want to do at the end and then maybe for a month later in the year revisit to old characters?  This option runs the risk of the players losing interest in the old characters as they become embroiled in the new adventure path.  Perhaps so much so that they would see a return to the old characters as an unwanted intrusion at the time.
4. Build a mega-dungeon with touches from the previous adventure path designed with high rewards (magic and XP) in an effort to get the players to twentieth level and play at that level for a while?  This options thrusts the players into an arena that is familiar but not terribly rewarding as far as their own characters wants and desires go.  It is a very easy path for me as the GM to take though.