Hi,
There is a tradeoff here which will sadly rule out many devices. WLAN needs lots of power so most devices are mains-powered (directly - Sonoff TH*, or indirect - USB). The market seems to prefer battery devices for sensors so many are small BTLE, Zigbee or Z-Wave.
A UK-specific retailer has a useful site broken down by both purpose and technology:
Sadly, mains powered devices tend to be HVAC controllers.
A product that almost matches is the Xiaomi LYWSD03MMC which measures temp and humidty, is cheap, and has a display. Sadly it is sold as BTLE, but FOSS firmware converts it to Zigbee - battery low-power protocols!
I’ve used ESPhome and Tasmota to create my own hardware with cheap DS18B20 / DHT22 sensors and small OLED displays. These work with WLAN and are powered by USB, but not off-the-shelf.
James