(Is it safe?) Preparing Breakfast in Bulk Seasoned Advice-Givers,

I make an excellent breakfast, but would like to prepare a 7-day supply in bulk, to eliminate the preparation time I expend every weeknight.

The ingredients are:


3 Cups Rolled Oats
Large handful of Sultanas
Large handful of Dates
3.5 whole bananas, thinly sliced
Enough milk to completely submerge all ingredients in a sealed, air-tight mixing bowl


I'm reasonably confident about how well the sultanas/dates/oats will hold up, as far as food safety goes. (If I'm wrong, I'll know in about a day or so). BUT, I'm a little worried about putting the bananas into the mixture. 

Obviously, bananas are quite perishable, once peeled, but what if submerged entirely in milk, mixed with the other ingredients, in an air-tight, sealed mixing bowl? Will they go rotten rather quickly, or will the described environment preserve them?

Keep in mind, I do not mind mushy, rich, super-soft bananas that have started to turn - I think these are quite flavourful. But I don't want to cross the line into sanitarily dangerous. 

I know I can get at least 1 day without them spoiling, but I'm aiming for closer to 7 - It is likely the bananas in the mixture would still be safe to eat by Day 7? If not, at how many days do you recommend that I should draw the line?

This would be stored in the fridge, top-shelf toward the back, which is the coldest part. Fridge set to a 4 out of 7 on the temperature dial, which is one notch before ice will form on water.

Many thanks,

David
I honestly can't think of any reason that the bananas or milk would spoil over the course of the week.  None of your ingredients seem to interact with each other in an adverse way.  You might try making a small batch, sealing it, and checking on it after a week.  That should give you a solid (no pun intended) basis of comparison.