There's also a couple of timer mods you could look at too. I think only one or the other should be used, unless you use the first to reduce the timers when using the second.
An Easier War: Timers Tested
Increases mission timers at all difficulty levels to their Rookie level value, 4 more turns than Legendary. Can be adjusted in its INI file.
As suggested to allow for running into the Allien Rulers, I did this myself by INI edits. I found that 4 more turns makes things rather comfortable, so I turned it down to 2 extra turns.
True Concealment for LW2 Tested
Mission timers don't go down while the whole squad is concealed. By default applied to missions where the Officer perk Intervention can be used. Can be adjusted for which missions are affected and whether certain levels of infiltratration are needed to halt the mission timers. Can also have a chance for the timer not to tick down this turn based upon infiltration, which could be very cool.
EDIT: I currently run True Concealment for LW2 along with
A Easier War: Infiltration which shifts the infiltration sweet spot from 5 to 6 troops. I leave the timers at default and configure True Concealment for LW2 to suppress timer countdown as a chance based on infiltration.