Limited space want longer throw question

Hello all,

I have a unique problem. My theater space is roughly a 13x15 (so small) but unfortunately I can't put the projector screen on the 15' area so im relegated to using the 13' area. My projector is an Epson 8350 and will be projecting to a 110 16:9 screen. If i mount at the very farthest, the lens will be around 12' away from the wall... I can still get the 110" however I will be zooming a bit... And as I understand its sometimes better to try and use as little zoom as possible.

My space is unique in the fact that it has a crawlspace behind the room. I'm thinking about putting the projector in there still ceiling mounted, and cutting a viewing hole. Here is where i come into the problem.
The house is built in 1911 and has balloon walls and all the heat from the floors below (basement, 1st, and 2nd floors) travel up that wall and make that crawlspace very hot in the summer time and cold in the winter time. I am not in the business of destroying my projector. I'm looking for some suggestions on what I could do to make the best out of a situation.

Am i just better off mounting it inside and calling it a day or is it worth the extra effort to try and mount it behind the wall. Any and all suggestions would be greatly appreciated.

Yes I was referring to the decrease in light output... Currently my home theater environment is definitely not optimal in regards to light, however in the future this will go into a dedicated theater room, most likely completely light controlled.

So to clarify my original statement I was not referring to image quality rather decrease in light.

Extra note:
Hoping in about 3 years to build a house fresh and have the theater designed like so many of you guys do, as much as I love building things myself.