How to find Minimum and Maximum of Consecutive Dates in SQL server

When we have a condition to find the min and max of date from two different consecutive date columns from the same table with different id as shown below.

Query:- Select * from Project

O/P:-     

Id	StartDate	EndDate
8	2015-10-01	2015-10-02
9	2015-10-02	2015-10-03
10	2015-10-03	2015-10-04
11	2015-10-13	2015-10-14
12	2015-10-14	2015-10-15
13	2015-10-28	2015-10-29
14	2015-10-30	2015-10-31

Now we have the condition is to find Min and Max from these consecutive dates

Query:- WITH set1 AS (

                                                SELECT dd dt,ROW_NUMBER() OVER(ORDER BY dd) Rnum

                                                FROM

                                                (select startdate as dd from Project

                                                union select enddate  as dd from Project

                                                ) fnl

                                                GROUP BY dd

                                        )

SELECT MIN(dt) mindt,MAX(dt) maxdt

FROM set1

GROUP BY DATEDIFF(day,Rnum,dt)

 O/P:-

Mindt	Maxdt
2015-10-01	2015-10-04
2015-10-13	2015-10-15
2015-10-28	2015-10-31

 

What other ideas can you add to this post that I may have not mentioned?