In determining whether an action to make a public accommodation accessible would be "readily achievable," the overall size of the parent corporation or entity is only one factor to be considered. The ADA also permits consideration of the financial resources of the particular facility or facilities involved and the administrative or fiscal relationship of the facility or facilities to the parent entity.
For additional information, take a look at the following resources:
FAQ: What is considered an “undue hardship” for a reasonable accommodation?
FAQ: What are the limitations on the obligation to make a reasonable accommodation?
Fact Sheet: Reasonable Accommodations in the Workplace