Multiple sensors, one base station they all report to, and a network connection to serve the results to any browser.

I personally detest the "Internet of Things" moniker, due to the soaring aspirations, security problems, and how often the term is flung about. But, unfortunately, I may have to apply that to this project.

One absolute requirement is that the temperature sensors I choose must be accurate finer than 1°C (preferably accurate to a tenth of a degree), and you can connect two to a single device at a time. Right now, I have a bag of ATH-10 sensors, but have read a lot of complaints about these falling out of tune, and relatively quickly. Meanwhile, the one held up as supposedly lasting in their accuracy (can't remember which right now, but it doesn't use I²C) doesn't actually provide enough accuracy for my satisfaction, so we'll have to see how it turns out.

Right now, I'm hoping I can use an ESP-01 (or similar) module per remote sensor, as it only needs an I²C bus for two sensors (one inside and the other below the device, sketches on that to come later), a pin for a button to short-circuit the normal delay between reports, and a WS2812b RGB LED (I don't think I need more than one), and that still leaves some pins left unused.

The base station is where I'm confused right now. Ideally, I'd want to use a Raspberry Pi board, but I'm broke and can't afford one, and nobody seems to have any in stock at this moment.

What it needs to do is host its own WiFi access point, and connect to another network (either WiFi or Ethernet), without the two connecting (for security's sake). An SQLite database to store the reports (along with CSV files for easy export), and a web server of some sort to connect browsers to.

I already have enough experience writing web app like systems, so while I'm not worried about that, I am concerned with having enough power to serve pages fast enough. Especially since I'm currently attempting to see if an ESP32 can do this...

Constructive suggestions are welcome, though I am budget limited. Currently tempted to build the remote sensor enclosures out of some diameter of PVC pipe.