Hosting a Jupyter Workshop at a conference: Are there Alternatives to Azure, Google, or IBM Cloud?

Unfortunately, my University’s High Performance Computing Department has declined to allow me to use our internal Jupyter Hub service for an off-site conference workshop for a group of 25 Users in September.

1st notebook: 01_raw_intro
2nd notebook: 02_hll_intro.html
3rd notebook: 03_tagmaps.html
4th notebook: 04_topic_classification.html

(sorry, as a new user, I am only allowed 2 links)

Now I am looking for a place to run these four notebooks. I tend to use Azure and setting up a Kubernetes Cluster, based on the Zero to JupyterHub with Kubernetes guide. But it is a lot of work for a one-time workshop (I think I would have the technical know-how though). Perhaps I am overcomplicating things - are there any good alternatives to payed cloud providers, or maybe Cloud providers specifically tailored for University Classes?

I need these notebooks to work 100% reliable at the time of the workshop. I would say the Notebooks are medium computational intensive. They are, however, bound to specific environments with lots of packages, and I need space for users to store intermediate generated data (not more than 5GB/User). 2-4 Cores, and maybe 3-6 GB Memory per User would be good.