It's just GRUB for boot on this PC, and that's how I'm selecting Windows or Linux - in the GRUB menu. This might break if I did a Windows version upgrade, but so far feature updates are not a problem.
I don't think the placement of the partitions mattered much from a technical standpoint. I just liked the idea of a shared data partition at the end.
But yeah, if you're thinking about just jumping from the current setup to the 1TB SSD it would be pretty easy to use dd to clone old to new by doing a live boot from USB and having the new drive in an external enclosure (the command would be something like dd if=/dev/sda of=/dev/sdb bs=64K status=progress
- but double-check which drive id is used for each by comparing the names and sizes with lsblk
first). That will copy the current disk contents to the first 256 GB of the new drive and leave the rest as free space. Swap in the new drive and test to be sure it boots to Windows. Then boot using Linux install media of your choice and install to the free space. If you're not sure about the distro yet, you might want to have a separate /home to make it easier to try other flavors without wiping out your user files.
If anything goes south you'll have the original drive to swap in and get to Windows.
Running MS Office in Linux will be a headache unless you have a very old full install version (not the current click-to-run tech). I would recommend giving Libre Office apps a try to replace Microsoft Office. I've found both Writer and Calc to have great compatibility with Microsoft features, and their UI is very intuitive. I only saw Excel workbooks have problems in Calc where very proprietary features were in use, like online stock quotes through the Microsoft back-end, and things like sparklines. Pretty complex formulas on a very large workbook were no problem. If either of you are using MS Office apps for work then definitely test compatibility before you make the jump. You can test that on Windows since Libre Office works on both Windows and Linux.
You can do it. The main thing to watch out for is correct in and out device names. If you switch them it's not going to warn you before overwriting the current drive with the emptiness of the new drive!
Also, you'll need to sudo that command. But
lsblk
is something you can do as a regular user.