Two thoughts.
#1. In many cases you can JUST remove the shelves.
Build a small low stool/table and mount everything on there. Inkbird and heater. No fan required.
Just run one cable through the door seal (like jockey mentioned) - bingo.
If you ever then need it as a fridge, lift stool out and turn the fridge on.
#2 do you bottle or keg your beer? It is nice to have a fermentation space for that step too.... & very very nice not to have carry them far!
Might be worth considering that before you start.