My systolic blood pressure hovers between 90 and 96 regularly. There is really no such thing as a "normal" blood pressure. There is such a thing as a "normal" blood pressure for each individual person. It seems odd to base a transport decision on one assessment finding that may in fact be a completely normal finding for the patient.
You do need to be familiar with how to handle a patient with a DNR in your jurisdiction because most areas handle them differently. As Dixie stated, Maryland has a special DNR protocol, so special that it takes up several pages in our protocol book. My state has a specific EMS DNR form that allows for two options, (A) for advanced life support, everything up to and including medications, EKG, and airway control minus intubation, until arrest. After arrest, no heroic measures, and (B) for basic life support, palliative care only. Until a few years ago, the only form EMS was allowed to honor was the state EMS form. They have since changed and we can now honor every states DNR form as a form B. If you do not know your jurisdiction regulations, you need to make the effort and find out who to contact in regards to your specific protocols.