post recession, fares tended to be the cheapest for those booking in advance. the bucket airlines have say 5 seats at £20 which they sell first, then 20 seats at £50 and so on. however this only works if the plane sells out. if it gets near to the flight day and lots is unsold then some airlines discount right down just to get b.o.s. (bums on seats). Whether the price goes up or down all depends on the popularity of your destination and date of travel, the economy, fuel prices etc. Have a look now at how much the same flights would be for say October half term and Easter and see where yours sits within this. By booking in advance you do have chance to spread the cost and also are assured of your flight. best advice i ever got from a travel firm - "don't forget that last minute holidays are usually those that no one else wants, thats why they are still left on the shelf!"
If you book scheduled flights then they just tend to go up and up. The only exception is if an airline puts a sale on and this tends to be for travel between certain dates. Bit of a gamble in your case. If you really can't find anything cheaper through skyscanner or expedia etc then it's worth looking at cheap package deals. Book the holiday and only use the return flights and transfers and not the hotel. If you can bear it the Canaries usually have lots of winter availability and package holidays DO go down nearer the date.