I can't really offer any advise on your finances except for what I've already posted elsewhere about early retirement and tracking expenditure
I find your husbands attitude a little strange when it comes to sharing finances but then again we all have our quirks, I know I certainly have some and like you Mrs C has made her peace with them all
But you mentioned in your OP that you would like to have "some nice family holidays" before they fly the coup, well I think you should both make that a priority over the next few years to have at least one "special" family holiday before full reality of life hits them
Myself and Mrs C are well travelled and though we enjoyed the hedonistic beach holidays, the ones we really remember and recall the most are the ones where we went on "tour" to places like Peru, Kenya, India and China to see Machu Picchu, Masai Mara, Taj Mahal etc etc
But one of the ones that surprised me the most and one that I had a very special moment in was a road trip down the east coast of America in 2011
We started in Washington and zig zagged our way down to Key West in Florida taking in as much as we could but it was Disney World that I remember the most out of all the places we visited on that trip and the highlight for me wasn't all the different parks and rides but the midday parade of all the different Disney characters, like everybody else I was standing there waving at Mickey and Mini, Snow white to name a few
But it was when "Goofy" came over to me and gave me a big hug that I had one of those emotional experiences that you can't fully explain but will remember for a very long time for all the right reasons