A very common advice I've read is to keep all the other extra money in a Philippine bank account that comes with ATM card that works on overseas ATMs. For example BPI Express Teller ATMs can be used to withdraw funds in any Cirrus ATM worldwide.
Once you are outside the country you can easily withdraw that extra amount via those overseas ATMs where your card network is connected with.
So it's still worth keeping a Philippine bank account even if you have decided to permanently move overseas.
Should you decide to do this, inform the bank that you intend to withdraw such funds overseas, some ATM cards are, by default, disabled for international use for security.
Alternatively, you might want to use a debit card with Mastercard or VISA logos with high cash loading limits such as the Unionbank EON. Just ask the bank to verify if their cards can be used overseas.