In the past, I paid the extra 8 dollars a month at a storage unit to have access anytime of the day or night.
It cost me, 26 dollars to rent a space big enough for a tool box, wash cabinet, and a blast cabinet. The less you come in or out, the less suspicious.
Followed a friend in there on a bike, a few hours later, came out in a car. The most important part is to make sure you never leave the bike HOT or running inside the storage unit, unplug everything before you leave, and bring cardboard boxes in to layer to floor to keep from making a mess on the floor.
one of the key things was to run recon on the local storage places to find one that is either, run by young people, or innattentive people.
You usually have to pay for a month up front, but if you wanted to keep it as a shop, you can usually get a discount for 3 months, 6 months or a year. They have power and lights already in the units most the time.
Happy hunting! this is the best way I could work on my stuff, when i lived in apartments, other then just riding bikes up the stair wells.