Is it possible to update my T440s's hardware/parts for Windows 11?

Sadly, no :-(. The machine just can't be upgraded. Your best bet is to do the free year of ESUs to buy time, or force install Win11 but given the age of this you're more prone to having an issue then you are with borderline PCs like 6th/7th gen PCs.

How I am evalutating PCs for the forced upgrade is based on how OFF spec it is -- for example, 5th gen and older are pretty much just too far gone. 6th gen is risky, 7th is just a smidge under the requirements and seems to have been proven to be fine. 8th gen and up has official support.

AMD is easy: Pre-Zen (A series) is no go for me, Athlons based on Zen are fine. Ryzen Zen based is also okey being a smidge under and barely making it because it (GASP!!!) lacks a fTPM. Zen+ chips are officially supported.

This guide has the steps on how to make a bootable USB with the bypass enabled: Windows 10/11 – USB-Installationsmedium erstellen (Rufus)

The current crop of machines I have personally come to shortlist are 12th/13th/14th generation Core Ultra PCs (though admittedly, I also love the new AMD PCs - the crop of Ryzen chips from the past few years is as good, if not better). At least with Intel, the difference between 12 and 13 is minor, and you're probably paying a premium for a borderline upgrade. However, 12>14 or Core Ultra (which features an AI NPU exclusive to the Ultra) is a more significant upgrade. If you are choosing between a 12th or 13th generation PC, I would try to get a deal on a 12th generation PC or see if you can get a pair of 12th generation machines for the same price as one 13th generation machine. If your needs are relatively basic, consider sniping a small lot of 12th-gen PCs from an ITAD that wants to dispose of them, such as a 2-PC deal for around $400.

If you ignore all of the AI garbage Intel and AMD are pushing and want a newer PC with 14th gen chips or Core Ultra, pick a machine based on merit and modularity (for example, I grabbed a B stock 640 G11 with 32GB/512GB for $358 from an ITAD because it has the 16:10 panel, a quality of life upgrade from my G9 being 16:9) -- DO NOT get stuck on the Copilot hype, it's mostly used for GenAI slop at this point. You can usually find good deals on these 14th-gen/Core Ultra machines on the secondhand market, especially business-class models. I scored my 640 G11 for easily 70-80% off, if not more, just because it was used B stock with a few extra blemishes. You can remap the Copilot key with PowerToys, so the issue is largely moot since you can make it do something useful. For Lenovo, look at the T14 with the 16:10 screen (Gen3 and newer is the preferred range), and at least a 12/13 or 14th-gen Core i or Core Ultra CPU, or an AMD-equipped T14. I chose the 640 G11 due to price and specs, but I'd have been perfectly happy with an AMD 645, even the Ryzen 5 7535U with 6 fewer cores vs the Ultra 5/7.

The issue picking one now is that the market dynamics with modern Ryzen chips like the 7000 series make it so that the AMD version is not only cheaper new OR used, but it's genuinely as good as the Intel versions of these laptops. I have both as I picked up a 645 G11 to see how badly I messed up. The difference is a few points here and there; not even a deal breaker, especially given AMD laptops are cheaper and most of them are 16/512, whereas a lot of stock 640s with the Ultra 5/16GB are 256GB from HP.

Also, don't settle - check daily until you find the one or two. I have grabbed machines with specs I have NO business owning for the money I paid like a Ryzen 7/32GB/1TB SSD for the average price of a nicer Ryzen 5 unit with my 645 G11.

It doesn't matter what you pick unless your needs require one or the other, or one has genuine advantages the other does not for you (ex: 640 G11 has the NPU good for like 15 TOPS, the Ryzen 7000 chips are NPU-less; the 840 and 845 both have NPUs with the Ryzen 8000 having one, but they're both weak and you lose Ethernet with the 800 series - you need to assume the cost of an Ethernet USB-C dongle with the 800 series. But in general, I would go off of CPU and spec as purchased - if the AMD version is the same 16/512 as the Intel, the AMD will probably be cheaper AND really compelling. On the other hand if the Intel machine is cheaper, go with that. It's literally the same short a few points. Pick one with a strong base RAM and SSD setup, but really focus on the CPU as the CPU is the soldered part.

Either way, regardless of your choice, perform a full erase of the machine using the NVMe secure erase option, put it online briefly, and check for MDM on the first day by going online in the OOBE. Once you see it is MDM-free, you're good to use it.