Have you ever introduced a new cat to the residence cat do it the same way.

If not

Confine the furball to one room that has no traffic in it put his litter box
and their food in there on opposite sides of the room.   This is the only
time it is acceptable to do this to cats most will  have bad bathroom habits
because of it.  IMO leave in there for the next 2 days visit very regularly
after a bit open room up  and YOU leave  let the furball investigate on
their own.
    If you can only let them explore small parts of the house at one time
do so  sit in one room and have some treats  talk to your furball and
reassure them it is ok.  Do this over the next couple days and you will have
one happy furball.  At night I would put the furball back into in the
enclosed room so no spooking can happen.  When we built out new house  we
made a room specially for the cats.  We did this and the furballs became
well adjusted  TOO ADJUSTED ( little devils ).  Make sure you start this
process after the move is completely done  that is all boxes emptied, etc.
Furballs have a tendency to end up in the boxes and can be thrown out with
the trash.  Hope this helps

In two weeks I will be moving and I will be doing what I have done in the
past.

Next weekend while the house is still empty, I will take Matilda there and
turn her lose so that she can explore and mark the walls and corners of
doorways using the sent glands on various parts of her body. That way, once
all of household items are in place and she returns, it will all be familiar
to her. I'll also be bringing along a litterbox and introducing her to its
new location.

Two days prior to the move she will go to the kennel and stay until 5 days
after the move. She's been really good with the disruptions in the house so
far (packing and a pile of boxes) but when it comes to the chaos surrounding
the move and the unpacking, she'll be better off at the kennel. She likes it
there so we won't be the least bit worried about her.

So, if you have possession of your new house anytime prior to the actual
move, I suggest you take him over.

Just my 2 cents worth. Good luck with the move!!

Judy