Working in an unheated not insulated shop at near rainforest climate comes with a number of issues – humidity being the most challenging. To avoid corrosion I had to keep my tools in the house, take them out to the workshop, and then, when day was done, bring them back with me again.
“Furniture-dry” wood was not think about; though to be honest, I had none of the seasonal dimension changes that are there now, with the new humidity controlled environment. A dehumidifier keeps the relative humidity <55%, and as the temperature in my new shop does not go <10 °C, the dewpoint is never reached.
Heating the old workshop (a cowshed) had to be limited to the work area. I used a 3 KW heat fan. It wasn’t too bad, at least my feet were kept warm. Gluing could be problematic, so I used a “winter glue” during the cold season of the year. Cyano-acrylate glues were not impacted by winter, but became useless as they did not endure the heat under a tin roof during summers.
An idea I entertained for the cowshed was to build a proper insulated workshop inside it. Perhaps that is an alternative for you. As for temperature and humidity, it would at least be a less energy consuming alternative.