I've only gotten one (free) upgrade and it was on my very first cruise in 2004. (this will be #12 for me, too) I have always been under the assumption that if you reserve a specific stateroom,
DCL won't ungrade you for free. You can request an upgrade at the port and pay the difference. Thoughts?
Paul - I noticed we are on the port side, directly across from you! I love staying on Deck 5. We stayed in 5022 on our last Wonder cruise and really liked the SPH. However, I'd love to upgrade to a verandah at the port. It seems like verandahs will be available so it will depend on the additional cost.
Upgrades: From everything that I have read on the Disboards, there is no rhyme / reason on how upgrades are given. Historically, it seems that most of these are handed out 4 / 5 weeks before cruise date, at the same time they are assigning the GTY rooms, although with the invention of the OGT & VGT classifications, it seems that these are only being handed out about 2 weeks prior to sailing date. (Note: most of the comments I have read about OGT & VGT cabins specifically mention the Dream & Fantasy.)
or, as you mention, you can pay for an upgrade at the port, at a significantly reduced price, assuming that there are cabins available.
Still showing plenty of availability on pretty much all verandah category cabins, still keeping fingers crossed.
We love Deck 5 as well.

Great location on the ship and easy access to everything.
Would like to join the FE group and the meet. We have 2 rooms.
Me (Donna) and DH (Gary) in room 6654
DD (Joy), DGS (Cameron - 9) and DGD (Gabriella - 7) in room 6604.
We just booked so I wonder how crowded the cruise will be. Trying to figure out what excursions to do. Any thoughts?

Welcome Aboard!
Excursion recommendations: Obviously dependant on what your family likes to do, but I would very highly recommend the White Pass Scenic Railway (Skagway). The scenary is stunning, and it's quite an engineering marvel.

There are a bunch of variations of this excursion, some have extra's like gold panning, etc.
In Juneau, I don't think you could go wrong by going to Mendenhall glacier.