The JTR still gives you this out:
If…adequate Government quarters are available on
the U.S. installation to which a Service member is
assigned TDY, but the Service member chooses to
use other lodging,
the Service member is limited to the
reimbursement cost of Government quarters on
the assigned TDY installation (44 Comp. Gen.
626 (1965)).
Table 2-14. on page 44
Other lodging chart.pdf