The overall mileage would suffice. Here is an excerpt from Pub 463 on Travel, Ent, and Car Expenses - seems like you situation fits perfectly with the example. The key really is the IRS wants contemporaneous daily records, so keep a daily log of total miles driven on your route - don't try to guesstimate end of week, month, or year.
https://www.irs.gov/pub/irs-pdf/p463.pdf
(page 26)
Car expenses. You can account for several
uses of your car that can be considered
part of a single use, such as a round trip or uninterrupted
business use, with a single record.
Minimal personal use, such as a stop for lunch
on the way between two business stops, is not
an interruption of business use.
Example. You make deliveries at several
different locations on a route that begins and
ends at your employer's business premises and
that includes a stop at the business premises
between two deliveries. You can account for
these using a single record of miles driven.
