Well, let's give it a try with some other creative options:
- Paint in the shed, make sure the kitchen unit is placed on a surface that can be transported, allow to dry inside the house.
- Paint partially in the shed, touch the unpainted parts for transport to the house, allow to dry inside the house.
- Cover a large area inside the house with huge sheets of plastic and paint inside the house.
- Paint in the shed, use the heat of a hair dryer to dry the paint. Be sure not to blow your paint away while it's still wet!
- If the kitchen unit is made of metal you may also choose to heat it up before you start painting. Be careful though, as you don't want to ruin the first layer(s) of paint. And you probably have to paint quickly or repeat the heating while painting.
The romantic solution:
6. Put candles in the shed for a local and temporal raise of the temperature.
And if all else fails:
7. Wait patiently for the paint to dry. (Like your option 3, but now the waiting is after the painting instead of before the painting and it will reduce your waiting time.)