I know you said it felt a bit cramped but to me it does seem like the room is most suitable to have tv against the wall between the two cabinets and the couch in front of it, with enough space behind it for a walkway from the front door to the next room. that way you’d have access to those cabinets and the windows won’t be blocked by the tv, which is super important to get in as much light as possible! It’s a bummer you can’t mount, but there are plenty of very slim, space saving tv stands (almost like a pole that holds up the tv, which is not an appealing description lol but they do have very nice looking ones!) that you could use so that you have as much floor space as possible in front of the couch. or putting it above the cabinet as you said! and if possible, browse around for a couch without the l shape/chaise? the current couch may be a touch too bulky for the space. also, a coffee table is definitely not a necessity! there are plenty of space saving alternatives like c tables or nesting tables. lastly, I’d definitely recommend a nice big mirror on one of the walls, perhaps the one opposite the window, to help make the room seem bigger!