Yes, but those other bookings will have no impact on your ability to extend your reservation.
Once you have secured a reservation, you have to imagine that, as far as you are cocerned, the room you have booked is the only room in your booking category. Also, the only people who can book Jan 8 by calling any sooner than Feb 8 are those who can also book Jan 7.
Here's how it goes: You book Jan 1 to 7 in YOUR room. Someone calling on Feb 7 will not be able to book Jan 7-10 in YOUR room because they cannot book Jan 7; you are still occupying YOUR room that night. On Feb 7, the other member will be told that Jan 8-10 are available in YOUR room, but they cannot book those days except by calling on Feb 8.
You on the other hand, call on Feb 7 and want to book Jan 8-10. Because you already have a reservation for Jan 7, you are allowed to book those additional days in YOUR room a day sooner than any other member.
There you have it: one call and you have extended your reservation to Jan 10 with no risk that any other member will book those day before you.
Once you have your first reservation, your only risk is that you forget to call on Feb 7 (or earlier) and don't call until Feb 8. At that point you are completing with every other home resort owner for Jan 8-10 and may not be able to extend you vacation. -- Suzanne