I am in a similar position; my M3P is only 3 years old. I really love my car, and there's very little I would change about it.
Still, like you, I find myself longing for something else. I took a '23 Model S out for a test drive and was very impressed. It outdoes the Model 3 in every way (especially compared to a newer model with HW4): larger screen, ventilated seals, faster computer, instrument cluster, better audio, air suspension, more range, speed, more room, upscale interior, and on and on.
I purchased the m3P because it's fun, but coming from a luxury brand, it needs more inside. It's just missing something, and to me, the S has that something. One other thing is I never found the Model 3 to be an attractive car. Honestly, it's homely. That S is one sexy, sleek, low-slung machine, and even though the design is aging, it's just a better-looking car. Then there's that new red.
The Highland improves on the current model quite a bit, but I have decided on a Model S LR. The rumored minor refresh, which includes the LED lighting and front bumper camera, will also be excellent additions.
Is it an intelligent financial decision? Heck no. But I'm blessed with a fair amount of disposable income and YOLO. I had considered the Plaid, but there's not much value in 20K for an extra motor and a CF spoiler, and with the Plaid, you can't get wood trim (ironically, I hate the wood trim on the M3). I will add a Cybertruck as a second vehicle in a few years.
I wish there were a few more models to choose from, but for now, I will much enjoy a Model S. But I will miss my 3 a little.