I think this is going to first depend on your child's natural demeanor and then to how you go about doing the move. We moved when our daughter was 23 months old. She is a pretty easy going child to begin with. We did make sure to put the furniture (as best as possible) in the same locations as the first room, but it took us awhile to get all the decor up. She seemed okay with most of that and slept ok...not great the first couple of nights.
If possible, try to baby proof what you can before any time goes by. You forget how long it took you to put your first house together and to child proof. And, every house is different and will require different meaures for safety. Try to think those out in advance and have a game plan. (Maybe a relative/friend can work on that while everyone else is moving your items in.)
We had a relative take our daughter for the day while we moved and had some help with moving the furniture (and putting the crib back together)from others. I was also pregnant during the move (due next month) and supervised! :)
We also used one of the spare rooms in the new house for a play room. We tried to keep a tub of toys off the truck so she would have them to play with ASAP. This also helped. If you can, try to have a relative either come over and put things away for you while you wrangle your monkey or have the relative watch the monkey while you put things away. It is nearly impossible to put a house together with pint sized help. You will constantly be stopping to check on your son or having him hand you things that you don't want him touching.
Your son will adjust just fine! We all love the set-up of the new house and enjoy it everyday. My daughter hasn't really skipped a beat! (And lucky you for only have a 2 mile distance between houses!!!)
Good luck!