Yeah it's pretty easy to set up a "base station" with a monitor / keyboard / mouse / etc. One thing I haven't researched is multiple external monitors connected to a laptop.
I'm personally fine working primarily on my powerful desktop machine 75% of the time, and suffering an older slower laptop 25% of the time. I synchronize the 2 machines by storing my work files in Microsoft OneDrive, and with Firefox Sync. If I worked 50% or more of the time on a laptop I might opt for a powerful expensive laptop, with a base station.
Unfortunately I have no experience with Inventor, but I'm modelling with SketchUp on an old Asus K73 laptop from 2011 (upgraded to the absolute max) and it's definitely tolerable, although noticeably less smooth than my beastly desktop. But different programs, and furthermore different workflows, can have very different hardware requirements.
What's nice about the desktop is it's more bang for your buck, especially if you want to maximize performance with the overclocking allowed by a desktop's superior cooling, and it's more modular to upgrade in the future. For example, 2 years ago I upgraded my GPU with a $250 used GTX 1070. Now I'm selling that for $200 and upgrading to a $500 GTX 1080 ti. In a year or two I'll upgrade my motherboard and CPU, and if I'm lucky that motherboard will be compatible with the next CPU upgrade. I've had flawless luck so far with used parts off ebay (knock on wood).
CPU: Most tasks benefit from a fast CPU (high clock speed, ie. MHz or GHz). Multiple cores beyond 4 are currently under-utilized but I'm betting that it will become increasingly relevant. I personally would try and get a CPU with a high clock speed & with 6 or more cores. Check benchmarks (passmark, userbenchmark) for specific CPU models.
GPU: Whether a discrete GPU is important depends on the software you're using, even within the 3D realm -- research the particular software you expect to be using. If there is no discrete GPU, the laptop will be using the GPU chip integrated into the CPU, which is typically far inferior to discrete, but sufficient for some tasks. For my SketchUp usage, a discrete GPU is pretty important. Fairly recently (2019?), laptop GPUs stepped up their game and they can be somewhat comparable to their desktop equivalents. I'm familiar only with Nvidia, and so I would look for a laptop with a GTX 10 series or RTX 20 series GPU, or equivalent Quadro. The "max q" series are in this same upper class, with a slight compromise for the sake of power and heat. Quadro (pro) vs GeForce (gaming)? General consensus is that gaming cards, which are cheaper, are fine for most 3D tasks. I know it's fine for SketchUp and Revit.
RAM: This spec also varies in importance depending on software, but generally 8GB minimum, 16+ is nice. Often RAM is upgradeable after purchase, and sometimes it's cheaper to upgrade yourself.
As for specific laptop recommendations, I think it can vary a lot each generation, within brands. One consistent winner for me is the the Lenovo Thinkpad series -- I like the keyboards and the Trackpoint mouse, and for the durable, accessible build quality. But Thinkpads with GPU means Thinkpad with Quadro, which will be a bit more expensive. Maybe check out the Lenovo Legion gaming line -- I was recently tempted by their discounted 17" 5i model @ $1000. Another gaming-ish brand, more expensive than Legion: my friend is quite happy with his Maingear Element, which has a nice feeling mechanical/optical keyboard and a gaming GPU.
I am torn between 15" and 17", but definitely prefer modelling on my 17". Limits choice of computer backpacks.