Moderator, Iberia Airlines, Airport Lounges, and Ambassador, British Airways Executive Club
Join Date: Feb 2010
Programs: BA Lifetime Gold; Flying Blue Life Platinum; LH Sen.; Hilton Diamond; Kemal Kebabs Prized Customer
Posts: 63,735
OLCI does make it slightly harder to upgrade (I'm presume you mean for Avios). So you can either not do OLCI, or persuade the agent to offload you to enable you to upgrade. Occasionally you hear of agents suggesting that it's not possible to offload, but in reality it's not that difficult to do. The availability is likely to come online around 01:00 hrs UK time, so the compromise is to OLCI at that point if there is no availability.
[Incidentally, it's always good to put a few specific words of description into the title, it helps other people searching in the future. Not a big issue, but it all helps!]