I would be replacing my mac entirely. Work would provide me a Windows 10 laptop that I would use for the 2 days I'm required in the office. When I'm at home the plan would be to sell the MBP and put the cash towards a gaming Windows 10 desktop. I would use the desktop when at home and not the laptop.
In terms what I spend the majority of my time doing when at work - browser (70%), office (10%), mail/skype for business (10%) and Citrix viewer (10%). I work with cloud based software so browser is king for me. I sometimes use Sublime if I'm doing some bigger javascript work but mostly use the editor within the browser.
What I like about using my personal MBP for work is being able to respond to iMessages and have everything in a decent desktop calendar app (personal, work, etc).
So the way I see it, there are some key apps that I'd need to think about.
Office - this would be better in Windows. The Mac version is still quite inferior.
Browser - I would move to Chrome.
Password Manager - I use keychain, I would need to migrate my passwords.
Calendar - I think the best option here is to keep work calendar within Outlook and personal in Apple and use my phone/web.
Music - I can continue to use Apple Music via iTunes.
I would miss retina, but I tend to sit quite far back from my screen these days.
Laptop that would be provided FYI -
https://www.uk.insight.com/en-gb/productinfo/laptops-and-notebooks/0007116996-00000001