^^It's much more of a major pain to have a bent derailleur hanger and destroyed rear derailleur. I always remove mine when traveling and have never had any issues reinstalling. It usually just requires a 5mm Allen wrench to reinstall. If the cable tension is too tight, make sure your shifter is all the way in the bottom cog. Depending on your bike, you can also temporarily remove the cable housing section from the right chainstay to the derailleur (if you have split housing) to get more room to reinstall. Or, if you have cable adjusters somewhere inline, set up your derailleur so that when it's properly adjusted you still have room on the cable adjuster to loosen the cable. Or, finally, if you know you are going to undo the RD cable, put a drop of colored nail polish on the cable where it is attached to the RD to make re-setup easier. (Put it before the RD cable bolt, not after, so it doesn't flake off when you pull out the cable and reinstall.)
Not meaning offense, but if it takes an entire day to install/adjust a RD, then a course at your LBS might be in order to brush up in this necessary skill for touring. They are very vulnerable and valuable pieces of machinery on the bike and knowing them well is an important skill to have when touring. Adjusting a RD is easier to do on the road if you turn the bike upside down so you can roll through the gears.