Dimensions for a small shop

I’m a career carpenter (14yrs) and my wife and I just recently finished building our house. Building it on our own took everything we had — energy, time, money, economic mobility — but we’re finally done. On that note, we had nothing left to build a structure that would house my big tools or our outside equipment. It’s been about 8 months and we’re thinking of throwing something together before winter. This will be a modular structure on skids so it can be moved to a more ideal location in the years to come. For now we have a good temp place for it. It isn’t going to be a woodshop right off… but once we build a barn/garage, the structure in question will become superfluous, at which point I will convert it to a shop. For medium to (not very) large projects what footprint would you consider, and why? I’m only concerned with the interior space now, exterior elements can be worked out later. Probably gonna try to keep it under 20’ in length and 10’ in width. Thanks in advance!