How long is too long to bourbon barrel age with new barrel?

I'm looking at a good price on a 5 gallon bourbon barrel, but i will be away from it for 4 months just a week after it arrives. Can I just throw a beer inside of it and leave it for four months with the beer still being drinkable, or will it soak up way too much bourbon character over that time? I can have someone top it off for me every now and then, so this seems feasible.
Aswell, the barrel will be kept in an apartment closet while i'm gone, looking at 75-80 degrees. I know that's rather high, but will it be an issue?

I am doing a bourbon barrel aged RIS now. I plan to barrel for 2-5 weeks, I will be tasting every week. I have been told its easy to overdue it. So my answer is yes I think that is too long. You need to test often.

So the way I am to understand it then, is that when you get a new barrel, you need to constantly have a flow of beer inside them-- the more brews in it equal a less intense bourbon character overtime and longerterm again as result? (I'm certain I've heard beers being aged for months, but is this just fresh oak or older bourbon barrels?)

I suppose if the original beer was over oaked, I could always blend it into a weeker batch. Best Case: good beer and a ready2go barrel. Worst Case: bad beer but still a ready2go barrel for my next brew?

4 months is a very long time for a small barrel, esp for the first batch. the smaller the barrel the more surface area per volume and the more oxygen permeation. you can do it, but you'll most likely need to blend it

Agree, there will be way to much exposure to oxygen and too much bourbon/oak

I just did a Scottish ale in a whiskey barrel. 10 days was good.

It's true you need to increase duration in the barrel after each use.

In your case I would wait. Let the barrel dry out and when you are back and ready to use it you can rehydrate it. 4 months is just too long in a 5 gallon barrel.