Introducing a regular dog visitor

[Foxblue]

Hello you lovely lot, looking for some advice.
I share a dog with my ex partner ( 4 year old working cocker) She very much took the split in her stride once she got used to the new routine, and is happy to stay with my ex partner at their parents house, where they have dogs she has known since either she was a puppy or they were a puppy. She also has my dads dogs (who again, she has known her whole life) stay over at my house on occasion when he is away, which again she is happy with (as she loves one of his dogs in particular) I'd describe her as very well socialised, and likes certain dogs, but is more of a people dog and happy to be on her own.
I have a new partner who has a (older, same breed) dog, they've been on walks together and get on fine. We'd like to spend more time at each other's houses with the dogs, including overnight stays.
I'm just hoping for some general advice and experiences really! Has anyone dealt with similar, how did you approach things, what should I avoid.

Note: am aware that not everyone agrees with a dog having two homes - I understand and respect that view, and agree that for some dogs it is hugely detrimental. This has been the setup for us for 18 months now and our dog has settled into the change very well - just wanted to say that up front, if she hadn't settled we would have changed what we were doing, as her wellbeing is the priority, not our personal relationship. If you think we are bonkers, that's absolutely fine! Dogs happy, and that's all I care about. Hence wanting advice on navigating further change.

We've taken our dogs to stay with friends who have a dog overnight before, as long as they get on and can sleep apart if they want to it's fine. At my friends his dog slept with him and our dogs slept with us, I guess with a new partner it's a bit different as you'll be sharing a room.

Where they sleep would be my main logistical thing, ours sleep on our bed, so when you get to three it can get a bit much. I also wouldn't want to be shutting them in a room without people overnight together unless I'm 100% sure they get on.

MILs dog is with us about 20% of the time as well, like a second home. I asleep in the spare room when she's here, because she's huge and they all sleep on the bed! Conversely, if ours stay at MILs they all sleep in the kitchen.

I wouldn't over-think it too much. As long as both dogs get on and don't have any behavioural issues like guarding, there shouldn't be too much of an issue.

We've had several dogs to stay at ours for various reasons and it's always been fine. We just make sure to split them up for meals/treats and make sure that our dogs' routine doesn't change too much - so he still sleeps in the usual place and has his meals at the usual times etc.

When our dog stays over at my parents they separate mine and theirs when they eat, sleep and go out. They settle really well especially after a long walk together although our dog took a while to take to their latest addition all seems fine now.

Thanks all, this is really helpful! Definitely got to be mindful of bedtimes - luckily both dog are used to sleeping outside the room and in the bed interchangeably.