Deploying Windows 10 in a digital license reality

I had this question after viewing Windows 10 Activation fails after cloning hard drive.

Good morning.

I'm looking for a best practice to keep 30 or so standalone laptops up to date with Win 10 in a digital license environment.  I apologize in advance for it being long-winded.

The Background:

I've been asked by a non-profit (think Internet café for this discussion) to support 30 or so standalone Dell 3330 laptop computers.  The organization has little tech available to them and although my background is networking and Unix, I've used Ghost before for clean Win XP and 7 installs and re-activated using the code off the sticker.  

These computers appear to have gotten to Win 10 via a Win 7 Dell license and Microsoft upgrade path (it appears to be called a "digital license" now).  Typically the computers sit in a charging stand and are given out randomly to folks off the street or constantly to certain staff, who get used to one computer or another.  The drive types are not all the same (mix of rotary and SSD).  Of course the ones that are given out sparingly or not at all over the past year take 9 - 12 hours to download and process all of the Windows/Application updates.  After spending an all-nighter over this past weekend, updating turned into a major fail.  At 3am I realized that the 15 that have mSATA SSD's are within 2GB of full (46GB used of 48GB available) and were thrashing.  My thought: Time for a 30*120GB SSD purchase to give these machines a year or so yet, in order to give the organization time to re-buy.  Then a clean install would follow.  The plan would be to reimage all and then maintain a master image (always updating) and redeploy when needed.  In the case of a computer that sits idle too long OR if there is a major event where the organization wants 30 laptops to support (i.e. a children's camp or other community computer event), simply re-deploy and save the bandwidth and the problem solving.  The question is, with digital licensing, activation seems hard to me without a real Win 10 retail license key.

I do not own a machine at home with Win 8 or Win 10 on it myself and everything at work is Enterprise and managed by smart and overworked folks in the ivory tower.

Assumptions (from my little bit of research):  Based upon what I have read on the Microsoft pages, here and on the Internet:

The digital license must be harvested to a Microsoft account before one can laydown a clean image.  However, there are a limited number of times one can do this (but I did not see a number given).  Sysprep does not seem to help, because activation will still be needed once the image gets laid down.

The Microsoft deployment tool path still exists (I think); however, that appears to mean building an automated process to reinstall apps in order to achieve a fresh install.  I assume it works, because Microsoft provides instructions for doing so.

I've seen talk of the benefits of using VM's in the deployment process, but it is not useful in my real job.  If there is a substantial benefit to using a VM, I can; however, Ghost and physical drives (I'm about to have many) are fine for maintaining configuration management and version fallback.

I can re-purchase Win 10 licenses (either as an upgrade or "Get Genuine", whichever applies here) for $16 each thru Techsoup.org, since the organization has an account to get their Office licenses.  Coming from Unix and now Linux though, giving more money to Microsoft for computers already on Windows 10 is somewhat repulsive.

I'm willing to learn what I need (sysprep, Win 10 deployment, etc) to meet the mission; however, I do not have the time to deep dive the Microsoft domain in order to formulate a best practice.  Honestly if I could meet their need without Microsoft on the box at all, I would be fine.  However that is not an option here.

The plan:

Swap in the new SSD's.  Reload a fresh and uniform Win10 image with all of and only their basic applications {somehow}.  Dedicate one computer to "always be current", for purposes of master image creation.  Maintain the client images either by daily use OR by periodically or on demand, blowing everything away and deploying the current master image.  Package it so that someone less technical in the organization can mostly maintain the process with some help as needed.  Then go back to my paying job and life, already in progress.

The question:

In the opinion of those of you in the Microsoft domain, what is the best approach to deal with the Win 10 digital license in order to get to clean, unlimited Win 10 deployments in the manner laid out in "the Plan".  I'm sure someone else has already worked this out, so a link to "the page" is all I need.

Thank you for your time.  I'm glad this paid service exists so that I can ask this sort of headache-inducing question.