How critical is temperature late in a fermentation?

Here's my dilemma: I have an experiment going, nothing major, I just wanted to know how sweet hopless beer is, so I brewed a half a batch. All has gone as normal, and it has been in the fermenter 2 and a half weeks. The problem is, the thermostat went out last week and we have not had a chance to get it repaired, so the fementer is now reading 79F (The whole house is warm, so I dont have any place to move it to and its been creeping up over the last few days). How much could this effect off flavors? It is my understanding that warmer ferments can cause estery flavors, but I was always under the assumption that this was in reference to the primary ferment you get in the first 4-5 days. I normally ferment around 65F or so.

Temp control is only critical for the first week or so. After that a slow rise to the mid seventies will help the yeast clean up their off flavors.

You should be fine. Its an ale yeast your using Im assuming?

Yea, Basically what I did was took an extract kit that I have made before and liked, and loosely halved the recipe. I used only one can of extract instead of two, and then used the full amount of specialty grains, and left the hops out. Fermented with a pack of Muntons yeast. All said and done I had a 2.5 gal. batch, and the majority of the fermentation was done before the temps began to rise. It's by no means a panic issue, I just like for experiments to be more controlled, but things happen. With any luck I may have a beer the lady friend likes, I hear it will be sweet, but have no idea just how sweet just yet, it will be bottled this weekend so I'll know soon enough, but being newish to brewing, off flavors are still kind of a mystery.