DTD £1k Main Event, 20k starting chips, 2 hour clock.
About 1 hour into the first level (50/100), early position player raises to 300 and gets 1 caller before it comes to me in the SB with

. I call and the BB folds. Original raiser has already spewed almost 1/3 of his stack so is down to about 13k. I have approximately my starting 20k.
Flop

I check. Original raiser bets out 700 into a 1,000 pot, preflop caller folds and I make it 1,700 which is called.
Turn

I lead for 2,500 into a 4,400 pot and he insta-shoves.
I made the call only for him to reveal

. A blank on the river and I am down to about 7k.
Given the super slow structure should I have folded to his shove?