Okay, so first of all, yes, I do live in one of those 10% of districts.
Secondly, you don’t even have a candidate, let alone a popular one. It’ll be a miracle if an actual leftist candidate can pull 3% of the vote to come in fourth behind the Libertarian candidate.
It is less dangerous to cast a protest vote if you’re in a district that is dramatically unbalanced, but if you think you’ll make a difference by doing it you are going to be sorely disappointed in November.