My wife is the best thing to ever happen to me and I only do this out of loyalty to her. I am sure Mr. Bumble and the others will be well cared for, but in my perfect scenario, they would live out their entire lives with me.It will be a huge change, but hopefully you may have some good surprises, especially when you are preparing for the worse!
It's difficult to make such a choice when your partner has very different wishes on where and how to live. I think it's courageous of you to give it a try. I'm seeing several couples of friends fall apart because neither will make the effort to change, or one has been making all the efforts for years and decide it's over.
It's good that you can take at least Skeksis and Chippy with you, though you must be sad to leave the others, Mr Bumble and his children.