Where in Africa? We flew through Heathrow to Cape Town on British Air for both our trips and had no issue booking seats right when the window opened (
@calypso726 will know the number of days it is). I usually spend a few days prior to the window opening to 'practice' booking the tickets I want so I have a good idea what availability will be and the miles that I will need (so I can transfer points in advance if needed). The key for me has always been to know when the window opens for the airline that I want and to book my tickets right on that day to get the best seats for the lowest amount of miles. I don't know that there will be any "mileage deals" next summer, but most, if not all, airlines use dynamic pricing with their seats available on miles.
Where in Europe do you want to go? When do you want to go? You should be able to get better value with your points.
@CaliforniaGirl09 flies to Europe frequently and should also be able to offer some insight.