What is your ultimate goal? This is the fundamental question you must address. I understand you said "in the same room" in the original post.
If you have never demolished an entire fireplace, it is more work than you were thinking of.
I personally have a woodie against inserts. If your goal is BTUs in the house, lower heating bills; I see inserts as a poor compromise. Inserts are cheaper than a full on fireplace demolition, but you simply will not be getting BTUs into your house efficiently from an insert the way you can from a free standing wood stove. You will be buying more cordwood, hauling more cordwood, burning more cordwood, hauling out more ash, BTU per BTU than you will be if you bite the bullet and put in a freestanding stove.
But you don't "have to" demolish the fireplace to put in the freestanding stove. You can. I did. I have no regrets. I have enough land to have an outdoor burn pit in the months my wood stove isn't running. In the winter months if I wife wants to see "the fire" I just twist a knob on the freestander.
Look very very carefully at your floor plan, with respect to your needs; and see if having an ambience burner, a fireplace, to help your resale value - and a freestanding wood stove to lower your utility bills - is a possibility.
How are you going to move heat around your house from where your existing fireplace is? How much harder would it be if you leave the fireplace alone and put in a freestanding wood stove over there? I cannot answer these questions for you.
If I owned, which I do not, a relatively small house in the northeastern USA, putting a modern efficient insert into an existing massive stone fireplace might make sense- if I was going to sell the house in a few years.
In the north half of Alaska, with an imperative goal of efficient BTUs into the envelope, ripping out my stone veneered sheet metal fireplace to put in a free standing wood stove gave me a payback/ break even $ point on the order of 5-7 years. I have saved enough on my oil bill to pay for the stove and the pro chimney install, and all the wood I have burnt, to break even in the 5-7 year window, but my wood stove(s) have been burning for nine years come May 2023. I did most of the demo and construction myself.
I am now 'in tall cotton' - the kind of cotton you don't have to bend over to pick, so less back pain- and the money I am saving this winter is real money. I have the service life expectancy of my stove pegged at around 20 years. In 2022 US$ I am saving about $2k annually, and expect to spend about $2k on stove maintenance in the next 11 years. With the demolition of the fireplace covered, new pro-installed chimney covered, all the cordwood paid for and the current wood stove also paid for, I am already $ ahead and am looking to become another $18k ahead in the next 11 years.
Having put in the infrastructure, in 2022 $, my next stove will be about $4k, will pay for itself in 2 years, and then $2k/ annually x 18 years, I will be $36k ahead on the heating bill with the next stove- if I can still handle 8 cords of wood annually (about 16+ cubic meters annually ) in my mid 80s. I might put in a pellet burner in 2033.
In general I see fireplace inserts as having a relatively low install cost, but relatively high ongoing fuel usage for BTUs into the house.
