There have been between 20 and 30 polls since the Labour surge began in late September. The small Scottish sub-polls within these have largely confirmed that there has been no Labour surge at the expense of the SNP but only redistribution among the Unionist parties with Scottish Labour averaging below 30%, the Tories at around 12% and the SNP stable around 45%.
The above prediction that the SNP could fall to only 37 MPs at Westminster is an outlier.
In terms of full polls, on 4 October, YouGov had Labour at 30% and Savanta ComRes had them at 26%. At the same time, UK Polls had Labour at between 48% and 52%!