Northern Border Regional Commission Reauthorization Act of 2023 This bill makes changes to the authorities and programs of regional economic and infrastructure development commissions. Specifically, the bill reauthorizes the Northern Border Regional Commission (NBRC) and establishes and expands NBRC grant programs. The NBRC must establish a state capacity building program to provide grants to commission states (Maine, New Hampshire, New York, and Vermont) to better support business retention and expansion in eligible counties and for other specified purposes. Each commission state shall provide to the NBRC an annual work plan that includes the proposed use of the grant. Additionally, the NBRC may make grants for the planning, construction, equipment, and operation of demonstration health, nutrition, and child care projects. Such grants must give special emphasis to projects and activities to address substance use disorders, including opioid and methamphetamine use. The bill authorizes these regional commissions (as part of economic and infrastructure development grants) to (1) design, build, implement, or upgrade transportation or basic public infrastructure or workforce capacity to support the adaptation to and mitigation of climate challenges; and (2) promote the production of housing to meet economic development and workforce needs. Each commission may accept transfers of funds from other federal agencies. Discretionary grants made by a commission to implement significant regional initiatives, to take advantage of special development opportunities, or to respond to emergency economic distress may be made without regard to specified percentage limitations. The bill limits the aggregate amount of discretionary grants.