Thanks everyone for the input.
In the end, my husband decided he did not wish for FIL to know and I respected that. We did not tell him until after the baby was born (which was actually at the hospital due to a last minute transfer but almost pushed out in the ambulance, haha!). He was actually quite shocked but non-judgmental (at least to my face) about it. They (him and his girlfriend) were shocked when I walked home with the new baby only 3 hours later and got multiple home visits from midwives in the following days, so they were kind of impressed by that.
I can't help but wonder they talk about how crazy we were when we're not around (they do this about others so I can only assume the same for us) but...... hey, good enough right??? 
Thanks!!!
Congratulations! Glad it all went well. And hey, who cares what they say behind your back - you can't please everybody. You did what was right for you and your family.
So when you say walked, you literally mean walked? Because I keep joking about walking home from the hospital (I'm 3rd trimester and currently walk there and back for all of my antenatal appointments) and people act horrified or as though it's the most ridiculous suggestion on the planet! So I'd love to say I know somebody who has done it!
Our hospital sounds really similar to yours actually - discharge within a few hours and then midwife visits from there.
And I could barely walk and stand up in the shower 12 hours later, so I'd suggest planning some form of transportation! 
Glad things went well, OP.
Lol, yes I do know that my little joke should probably just stay as such!

My mother says she can't walk for a week after she has a baby.
So far my brothers are fighting over who gets to drive us home from the hospital, plus we actually do plan on buying a new car by then, so I think it will be fine. I'd love to see people's reaction if I did do it though!