I also got PR under federal investor program and applying in June. You can apply from anywhere Canada after 1095 days physical residence no matter which province initially nominated you for the program.
However, in recent application form you will need to declare whether you worked in Canada or not ? If you remain as an investor for last 4 years then I think you will need to mention this under "Work" and attach NOAs. However, if you have done any activity in Canada (self employed type/investments/etc) then attach whatever activity related documents you have along with NOA which might help to assess your position by CIC. That's what CIC agents advised me on my numerous queries.