I have successfully studied online, though Oktas8 raises some really valid points. Personally I would be dubious about doing a BSc remotely; having done some BSc maths and physics subjects internally I think the content is too techincal and/or prac based to complete online. I suspect that's why very few universities offer a BSc externally. Additionally, Maths and Physics are both competitive work areas (especially physics), particularly if you're not on campus making contacts and schmoozing up to the right people.
I would suggest looking at a B App Sci online, which a number of institutions offer externally with various different specializations. They're a bit more low-key than BScs but still fairly marketable.
At the end of the day, a degree is a degree, unless it's an obvious B. Basketweaving. If you get a good GPA you can use it to get into other stuff relatively easily.