Emergency fund (EF) should always be easy to access - When you need it you should be able to quickly withdraw it. How liquid are your long term investments? If they are liquid, you can keep 100% of your emergency fund in long term investment. If it is not liquid, continue to keep your emergency fund (EF) in your high interest account.
While deciding the EF amount, I hope you have considered the following
1) It should be a function of your monthly expenses - Generally 3-6 times of your monthly expenses
2) How risky is your job? If you have a stable job, you can maintain a smaller EF. If your job is unstable, maintain a bigger EF