Just moved to a new place...moved my fairly large Sears upright 60 gal air compressor to the new garage and just noticed that there is no 220 in the garage, only 110 outlets. Checked my panel for the house and it is slam full, no extra slots for a 220 breaker and an additional line to the garage.

Looking for advice on my options:
1) Replace or re-wire the motor? I wonder at the cost of replacing the motor with a 110 v motor. Should it be three-phase? I need to look at the info on the siide fo the motor more closely. The current motor is 220v, single phase. I think the compresor label says it is a 7 hp? I had it wired in my previous home detached shop which had a sub panel with plenty of extra slots for a 220 breaker

2) Couldn't I get a step up transformer to plug into an outlet in the garage? Looking at a 1000 watt tranformer was only like $60 online.

This compressor is not used for commercial duty, just home/hobby use.

Any advice would be appreciated!