Grandfathered employer healthcare plan is substandard and not affordable

My employers insurance plan will be considered grandfathered. However, I am an employee who works in a remote rural area and currently all of my coverage is considered out of network because united healthcare is not widely accepted. This means I may have what appears to be affordable healthcare but in reality it is not affordable and is substandard. It would be cheaper for me to buy from the state exchange because Blue Cross is offered and is widely accepted. It is my understanding that I will not be eligible for subsidies under the exchange because my employer provides a health insurance option. My household income would qualify me for subsidies otherwise. Is this true? Will i be forced to either continue paying out of network prices and not be able to benefit from better coverage under the exchange and the subsidies?