You don't need any RRSP room to roll your MPF into your RRSP.
The full amount can be rolled into RRSP. Bring all your MPF documents
along with you and show them to the bank.
You may have to speak to an investment advisor at the bank
https://pegasiprivatewealth.ca/perspectives/f/mpf-in-canada?blogcategory=MPF
Withdrawing Your MPF as a Resident
However, if for any reason you could not withdraw MPF prior to becoming a resident, and make a full withdrawal after becoming a resident, you would be liable for tax.
The moment you become a Canadian resident, you are liable for taxes on worldwide income. MPF is considered a foreign pension according to the CRA and any withdrawal is included as income in the resident's tax return(2). In other words, your MPF withdrawal is fully taxable, regardless of principle and capital gain. This interpretation has taken into account the 2012 tax treaty between Canada and Hong Kong. Article 17 of the treaty laid out that pension arising from Hong Kong paid to a Canadian resident may be taxable in Hong Kong, however, it does not eliminate the right for Canada to tax the very same pension(3).
Transferring to RRSP
The good news is that according to the Income Tax Act, you may be eligible to transfer your MPF to an RRSP and defer tax. You would be required to report the withdrawal as income, at the same time get the same amount of deduction to offset it(4). A Registered Retirement Savings Plan (RRSP) is an investment account that allows you to defer taxes on investment gains (such as capital gain, dividends, or interests) and future withdrawals are considered as taxable income.
For example, if you have $300,000 in MPF and it was transferred over to an RRSP, you report the amount as income but at the same time, you get a deduction to offset it. Five years later, your RRSP grew to $400,000 in market value and you decided to withdraw $50,000, you would not be liable for any taxes on the $100,000 investment gain but the withdrawal of $50,000 would be your taxable income for the year.
(1) Determining Your Residency Status, Canada.ca,
(2) January 17, 1992, Paragraph 9, IT-499R, Superannuation or Pension Benefits, Income Tax Act
(3) 19 March 2014 External T.I. 2014-0522671E5 - HK Pension and Tax Treaty
(4) Section 60 (j)(i),Transfer of superannuation benefits, Income Tax Act
https://www.sunlifeglobalinvestments.com/content/dam/sunlife/regional/canada/documents/slgi/810-5100-06-21-foreign-pensions-plans-web-en.pdf