The other point to note is that by the popular vote, most people did not vote for the SNP in Scotland. The polls up to the election have shown a slight preference to remain in the UK as well (that could change a bit now admittedly). I'm sure you could put together a team to that would be able to reach out to a lot of people up there.
Polls have also shown that around half of Labour members support independence - while some SNP voters would be No supporters, I imagine the figure either way probably wasn't far off the 50% mark.
I struggle to see the SNP mounting consistent poll leads for indy - I suspect we'll see a brief bounce before it settles at the 45-50 mark again.
But I think where the SNP could be boosted would be a campaign. I just struggle to see an even remotely successful unionist campaign if it's led by people who aren't active in politics. Ruth Davidson won't be able to mount a successful argument for the union when there isn't a single party in Westminster now that chimes with her beliefs. I also don't think the Scottish Tories would allow her to lead the campaign at this point - they've moved on and as they go in a more pro-Brexit direction, getting someone back in who opposes that won't be ideal for them.
Similarly, Scottish Labour are led by a leftist - whether he'll stay or not is another matter, but for now Richard Leonard won't want Gordon Brown stepping in over him to lead any unionist campaign.