NO- a new reservation will have to be made for the 1BR- no such thing as an upgrade in advance. If the original member doesn't have enough points to rent for the 1BR you could rent enough for 1 night from that member and try to find another for the second night- otherwise, points would have to be transferred from one member to another to do what you want. Since you already have a reservation (and, presumably a contract for that rental) changing the reservation to a different room type may be difficult- if it's even available at all.