We have been Publishing to Web from the Power BI desktop for years. Our models automatically refresh to the current version. The models we publish are substantial, but not near the limit for overall size--between 250MB and 600MB. Publishing has typically taken about a minute or so...more or less. Recently it's been very difficult to get the models to publish. I can let them churn for 15 minutes without completion. I have resorted to hitting cancel, then save (which starts some short save cycle) and then retry. It can take three or more tries to get a successful upload...which takes about a minute when it works.