What is the smallest but most powerful laptop to run Creo* 11

I suggest sticking to PTC certified hardware. I don't really know the answer

I think your options are:

HP zbook 14"

Dell Precision 14"

Lenovo Workstation 14"

MSI workstation 15"

There are likely others

I've never seen one used for Creo but Microsoft surface has a certified version

https://support.ptc.com/WCMS/files/176376/en/Microsoft_11.html