The steady-state analysis is not able to tell you how long the system would take to reach steady state via transient heating. You would have to run a regular (transient) simulation and time this yourself (either manually or via a tic, toc function in a script).
There are lots of things that may help to improve simulation speed and the duration of a steady-state analysis, but it is all very model-dependent. This can include the solver type itself, solver settings, steady-state analysis tool settings, the number of states in the model, electrical/thermal time constants and the complexity of the circuit and control model itself. If you are able to include your model file here we may be able to advise, but we cannot just provide generic feedback based on your statement and screenshots alone, unfortunately.
