Options while travelling are somewhat limited by the insurances.
The ACA set boundaries on programs crossing state lines and if on a program that requires a primary care provider for anything other than routine office visits then you can be forced into a limited set of providers.
For minor issues, doc in a box outfits like "Patient First" can be used for minor emergencies, and will get you in quickly, but for typical physicians offices, most are so worried about payment levels that they are skeptical on taking new patients.