Wifi or Blynk always disconnects

My preference is the Wemos D1 Mini or D1 Mini Pro (which can be used with an external antenna by moving a tiny resistor, and is useful for projects where weak WiFi may be an issue).

Or, if you need more GPIOs or Analog inputs then an ESP32.
Some ESP32s are also available with an external antenna socket.

Generally they are cheaper than Uno based boars and far superior in almost every way, and smaller too.

Pete.