How long did anyone stay on the puree stage?

It's very variable depending on individual doctor/clinic/hospital. Mine was at least a week and progress to soft food if all was okay with puree.

Two weeks

Mine was one week liquids, one week purée, and two weeks soft food.. after that back to solids just no starch and avoid anything high in sugar

We never had a specific puree phase; rather it was just one of the things we could do during the month or so long transition toward "real" foods. The pureed lettuce (ewwwww) that was served up in the hospital kinda put me off the idea of pureeing anything! I got along with straining or mashing up the chunks in heavier soups until I could establish that I could tolerate not doing so.