I been happily married 15 years. My in laws are pretty good. My father in law passed away earlier this year. He was a great man. Helped me become a man almost as much as my dad.
Now my mother in law is all alone. She's a pain in the ass, but she's my wife's mother. She wants me to do something...I do it. Life is too fucking short to spend your time fighting with your family.
You can end up being the one 'laying down the law' to them and not give an inch. You usually end up all alone being this way.
Instead you could choose to be the one that says, 'fucking a right we're gonna be there to spend the holidays with you ! I can't fucking wait !!' Make your fiance happy, make her parents happy.
Who do you want to be, the guy that's always drawing the line in the sand, or the one that makes everyone happy.
Also...on the dog issue...find a fucking kennel near your house. Get the dog used to going to the kennel. My goddam sister has to drag her pain in the ass dog over to my mother's house every time she visits. She only lives fucking 20 minutes away, but can't leave the fucker home alone for 2-3 days. I'm fucking allergic to dogs. Some people really don't like dogs. I know the bias on this site is to love dogs and I got nothing against them...I just don't want to spend anytime with one.
One last bit of preaching before I get off my soapbox...I skipped my dad's mother's funeral because I made good money on the weekends. At the time I felt justified and righteous and my old man was cool enough to let it slide. To this day I wish I could find a way to apologize to him, but even thinking about it now gets me all teary eyed. My great aunt is getting ready to kick so I'll probably break down and tell him how sorry I've been these past 10 years at her funeral.
My point is...you're never going to have enough money...you will have enough time to let family know how much you love them...make sure you're thinking things through way to the end before you put money over family.