Changing column width
If you're doing it through a T-SQL statement such as below, then no table drop will occur and you can safely do it in a production environment:

alter table &lt;table&gt; alter column &lt;column&gt; nvarchar(biggernumber) [not] null


If you do it through the SSMS Design Table GUI, it will depend on what script it decides to use to implement the change. Sometimes it will insert data into a temporary table, drop the original table, create a new version of that table, and insert it back into the new one. An easy way to find out what it will do is to click the "Generate Script" button and look at the T-SQL it plans on executing.