The Narrow Gate

Christ said "I am the narrow gate....No one can come to the Father but by me" (Matthew 7).
It occurred to me just now this can mean two things;
Either that only a few will be able to enter through this narrow gate
or
that it will just take longer for everyone to get through. (Imagine a barn door versus a turnstile.)
I know that Christ continued on to say that "those who find it [the narrow gate] are few. So it would seem that's the end of it.
But what about my first alternative? I'm hoping that because 'a thousand years are as one day to God', then He is not "slow to act as we perceive slowness, but is patient, not wanting to lose any of his people." (2nd Peter 9) I'm hoping that one day, in time, finally, EVERYONE will come to recognize Jesus as Lord and enter the kingdom of heaven. Even if the gate is narrow.