On Implied status, you can live and work inside Canada
When outside, you may not be having a payroll
Also when you get your WP, you will need to apply TRV to re-enter
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/temporary-residents/foreign-workers/public-policy-competitiveness-economy/c47-c48.html
Apply and see what happens in your case
If he has a Closed Work permit, the girls need Study Permit
School Admission is not needed
How long is he here?
Show enough funds to sustain a family of 5 - where he lives in Canada
Attach a lease document to show where the family will reside
Has he paid taxes? If yes show that proof
6 months...
Can get passport stamped
Traveling is risky unless you have finished virtual landing
What is your VO ?
If montreal, check other threads
Lot of such cases including a few that I personally know of