Neighbour noise is always worse in the winter. The sound carries much more because cold air holds less humidity - humidity dampens sound over distance.
Also people generally spend more time indoors when the weather is cold, so the noise can become incessant, especially over Christmas. That's usually the worst period. The kids are on holiday & bored, tempers fray, they're running around fighting, thumping up & down indoors instead of playing outside.
I've had really unreasonable levels of neighbour noise everywhere I've lived for the past 20 years. Not kidding, it's been maximum volume speaking voice is SHOUTING, blaring TV, fighting, door slammers next door everywhere i've lived. In contrast I'm extremely quiet & very much adverse to disturbing others. Wtf.
It's taken me too many years to figure out that me being superquiet & overly considerate is part of the problem so these days when the noise gets too much & begins to annoy me, i play music just loud enough to drown most of it out, specifically so that i don't get annoyed.
I use a tiny Bluetooth speaker that easily fits in the palm of my hand. I don't blare it at top volume, I play it at the minimum volume that masks their noise. Incredibly the current lot bang on the wall when i play music, so i guess even the slightest sound permeating through to them from my place is deemed antisocial, all while non-stop they scream at each other, stamp around, bash the same chords on the piano for hours, play the surround sound tv at top cinematic volume & leave their 2 dogs unwalked & barking in the garden all day.
I have found that people who scream & make a racket all day are unlikely to change just because their behaviour bothers others. Hopefully your mileage will vary. Attempting to respectfully ask for change has actually made things worse any time I've tried though so now i don't bother. Maybe you'll have better luck as the wife has expressed awareness of their noise to you. That does offer hope. In your position I'd try to catch her alone on the street to discuss it, rather than post a note or go round & knock.