Mini mash brewer - use igloo drink cooler for mash tun?

[kXb]

I am a partial boil mini masher and always find the 45min mash process a pia on my propane burner. I am having to monitor temperature constantly and turn the flame on and back off again.

I was going to use my 10g igloo for this process but from what I've read, that will result in too much head space. I bought a 9" stainless steel false bottom, pre-assembled gate valve, fittings and tube from my LHBS so that I can convert a newly purchased 5g igloo into a mash tun but after looking around a bit more, it seems like I don't need anything but the cooler.
One video I saw used a 3g cooler but the grain was rinsed twice and extract was added later in the boil.

I want to use the same process as I always have....mash ~45 mins at 150 degree, rinse grains, heat to 170 degrees, stir in extracts, boil with hop additions, chill, place in fermenter, add water to my target volume, etc.

So now I've gotten myself all confused. Do I need the false bottom and other things I bought at the LHBS for what I want to do? Is a 5g cooler too big? Should I ignore the video using the late extract addition method? I am probably worrying about this way too much but I haven't screwed up a batch yet and don't want to start now!

I will appreciate any advice

 

[Yooper]

How many pounds of grain do you typically use in a brewday? I would think a 3G cooler would be big enough, but a 5G cooler might be really useful if you're using a lot of grain.

Otherwise, if it's a small amount of grain, I'd go ahead and use any cooler but put the grain in a bag or bags if there is more than a couple of pounds, and not worry about a false bottom. If it's light enough to pick it up and pour, you could do that with bags.

Since you've got the false bottom, I'd convert a 5 gallon cooler if it was me.

 

[chickypad]

If you don't want to mess with the cooler you can always stick the pot in the oven if it fits. I used to mash my small batches in a bag-lined 3 gal cooler but found it's just easier to mash in the pot. I preheat the oven to the lowest setting (170) then turn it off when I'm doughing in. I don't even lose a degree over 45-60 min.

 

[kXb]

I'm terrible about remembering details of recipes I've brewed but my best guess is the typical grain bill is in the 4-5# range. I am not convinced I'm ever going to go all-grain but I guess I'd like to leave the option open for me in the future