Are you sure?? Doing lots of quality searching in this forum before asking is always recommended as there is rarely an issue that hasn’t already been solved.
Are you sure a simple reset will not reconnect??
Blynk.begin() is a blocking command, so if there is no connection the processing stops. But of course as long as the rest of the network is back and working, then so will the device be upon reboot.
If you need automatic reconnection, then you use Blynk.config() instead and other stuff to monitor and attempt reconnection as needed.
Here is an example for ESP8266…
PS… The delay in the void loop() is a BIG no no!!
As is showing your WiFi password and cloud based AUTH code to the forum 