It depends. The only way any of these miles would be considered non-commuting, is if your husband is going outside of the metropolitan area where he normally works. Then it would be considered a temporary work location, because it is a temporary area. Please view the IRS link below for more information about the distinction.
https://www.irs.gov/pub/irs-drop/rr-99-7.pdf
General rule: A taxpayer’s costs of commuting between his or her personal residence and the
taxpayer’s place of business are nondeductible personal
expenses. However, the cost of going between one business location and another business
location generally are deductible.