Just lifting everything an inch or so off the floor may be sufficient. I did score some of the super fancy thick linoleum on clearance and it warmed our under-insulated 1979 mobile home floor a lot.
Share a floor plan sketch with us if you can I’m not a great visualizer.
I had a corner door also, so no U. Here’s my floor plan and a couple pics in case they’re inspirational.
Should note though that I’m mostly an autoflower grower, otherwise I’d never get away with the limited height spaces.