Just for the sake of completeness, and also because it happens to be a favourable one, here's what is presumably the last Scottish subsample from a GB-wide poll that was conducted during 2017. It's from YouGov...
SNP 38%, Conservatives 24%, Labour 24%, Liberal Democrats 9%, UKIP 5%
Thirty-two of the last thirty-five subsamples have now put the SNP in the lead.
In the Britain-wide results of the poll's supplementary questions, one thing that leaps out at me is that Vince Cable clearly isn't setting the heather alight. 19% of respondents think he's doing a good job as Lib Dem leader, 29% think he's doing a bad job, and 53% don't know. The stock excuse for the high level of don't knows on personal ratings for a new Lib Dem leader is that he hasn't had a chance to build up his profile yet, but that doesn't really apply to a readymade household name like Cable. I'm inclined to wonder whether the bulk of those 53% of people weren't actually aware that he's become leader. Either that or they can't think off the top of their heads of a single thing he's said or done as leader.