My experience at LAS:
Add a buffer of a month or two with anything they say. I have never in my life seen an airport that takes so long to finish a project.
ORD takes out cement around gates and replaces it withing 4 to 6 weeks, LAS 3 to 4 months.
The bridge in LAS connecting Terminal B to C has taken years, ORD was built runways in less time than that, and DTW built a whole new terminal in that time.
I only hope that the 25L closure only last till May, but I have my doubts based on past experience.