Labour don't need to "win big" in Scotland to "have any chance" of forming a government. That is simply not correct, tho it would help.
They probably don't need to "woo" SNP voters either, given the current state of that party and the dismal prospects now for independence.
Promising to support a referendum, for example, is no longer a thing.
It would help tho of course to make inroads.
The problems for Labour include:
Being able to do a "blue wall" job, as the Tories did a "red wall" one.
If a lot of people there decide to back the Lib Dems then the outcome is unpredictable.
People who think SKS would be a good PM only match those who think RS would.
A lot of undecideds, whom these polls often don't take into account, may be more likely to stick with the status quo.