I work remotely in SC but have been asked to begin coming into our physical headquarters in WI 1-2x/month. Since this isn't my "home" location is the travel deductible?

No. With the Jtax Cuts and Jobs Act of 2018, all W_2 job related expenses are no longer deductible. I would suggest you talk with the employer about reimbursing you for this, or the business provide you with the needed transportation, such as bus or plane tickets.

Sorry---W-2 employees cannot deduct job-related expenses on a federal return.  Job-related expenses were eliminated as a federal deduction for W-2 employees by the tax laws that changed for 2018 and beyond.  Your state tax laws might be different in AL, AR, CA, HI, MN, NY or PA.

https://ttlc.intuit.com/questions/4482873-which-federal-tax-deductions-have-been-suspended-by-tax-reform