Peripheral Neuropathy: This condition is common in the elderly and can be caused by various factors including diabetes, vitamin deficiencies, and age-related wear and tear on the nerves. The symptoms of numbness, especially worse at night and referring into the legs, along with dry skin, are consistent with peripheral neuropathy. The patient's age and the nature of the symptoms make this a highly plausible diagnosis.

Hypothyroidism: This condition can cause dry skin and neuropathic symptoms. Although not as directly linked to numb feet as peripheral neuropathy, hypothyroidism is common in the elderly and can cause a variety of symptoms that might align with what the patient is experiencing.
Vitamin B12 Deficiency: A deficiency in vitamin B12 can lead to neuropathic symptoms, including numbness in the feet. This condition is more common in the elderly due to decreased absorption and dietary intake.
Peripheral Arterial Disease (PAD): While PAD typically presents with claudication (pain in the legs when walking), it can also cause numbness and dry skin due to reduced blood flow to the extremities. The patient's history of high blood pressure increases her risk for PAD.

Diabetic Neuropathy: Even though the question does not mention diabetes, it is crucial not to miss this diagnosis due to its high prevalence and the potential for severe complications if left untreated. Diabetic neuropathy can present similarly to peripheral neuropathy and requires immediate attention.
Spinal Stenosis: This condition can cause numbness in the feet and legs, especially when walking or standing, and can worsen at night. It's a critical diagnosis not to miss because it can lead to significant disability if not properly managed.
Multiple Myeloma: A type of blood cancer that can cause neuropathy among other symptoms. It's less common but critical to diagnose early due to its potential for severe outcomes.

Sjögren's Syndrome: An autoimmune disorder that can cause dry skin and neuropathic symptoms, among others. It's less likely but should be considered if other diagnoses are ruled out.
Heavy Metal Poisoning: Exposure to heavy metals like lead or mercury can cause neuropathy. This would be an unusual diagnosis but should be considered if there's a known exposure history.
Amyloidosis: A condition characterized by the deposition of amyloid proteins in various tissues, which can lead to neuropathy. It's rare and typically presents with a broader range of systemic symptoms.