Moving out, not sure what's best for cats

Long read here, but we're really not sure what to do and would be grateful for thoughts from cat people with an outside perspective.

In a few weeks, I'm moving into a small flat while my partner stays in the house we own, only about a quarter mile away. We are fortunate to be close friends, still more like family really, even though the romantic part of our relationship has run its course. And we're both worried about what would be best for our cats.

Both are pandemic-era rescues. Noodle is 17; we've had him for 5 years after his previous family abandoned him at the vet. (The very first time they ever brought him in. When he was suffering from a diabetic crisis. And he had a brother who did not come with him. We hates them.) He was 12 then and understandably has serious anxiety around vet visits and routine changes in general.

Soup is around 10, though we really don't know. We've had her for about 2 years. She was a hoarder cat who was absolutely miserable in the shelter--almost unadoptable because of how scared and withdrawn she was. She's blossomed here and is surprisingly resilient and chill about vet visits, strangers in the house, just about anything really.

They don't spend all of their time together, but they're definitely very good friends who snuggle up at least every day or two for naps and grooming--as you can see from the picture. The problem is, Soup is bonded with my partner, while Noodle is what I would describe as unhealthily bonded with me (probably because I spent a week nursing him back to health after he was abandoned--if I'm home, he isn't happy unless he's on my lap or sleeping in bed with me).

We genuinely can't decide what to do here: the house is absolutely better for our cats. It very quiet with lots of sunny windows and good bird-watching; it's the only home they've known with us. My new place is in an apartment building. It's smaller and north-facing on a busier street, and it's a completely new and different-feeling environment. The only reason we're struggling is because of Noodle's age and near-codependence with me. (Please know that we've spent most of our lives with him trying to help him feel more confident and independent; he doesn't want to be, or more likely can't feel safe enough to change. I truly fucking hate his old family.)

We *could* split them up, or share custody between our places somehow...but both seem very stressful for the cats as well. I'll be visiting frequently, of course, but part of why we're doing this is to get a bit of our own independence back -- so it won't be the same for them as me living here.

I just want them to be as okay as they can be :( Thanks kindly for any thoughts, all.