I am looking over at BlynkSimpleEsp8266_SSL.h and see that RX buffer size is defined to be 2048 (blynk version 1.3.2)
#define BLYNK_SSL_RX_BUF_SIZE 2048
Surely the good folks at Blynk know their servers won’t negotiate down below 2048 that’s why they hard coded it this… or did they?? 
Not that I don’t trust them but maybe they picked a number that balances performance vs memory usage? I havent found any documentation on this (perhaps I didnt look hard enough?) Has anybody tried out a lower number (say using 1K? With little memory to wiggle with on a nodemcu, any K helps).