I have done it several times.
Copy all folders httrack creates. not the site folders but the cache folder
and the other files cookies.txt etc if any and paste it where you want the new
download to be EXACTLY. I have my computers networked so it was just a copy
paste for me. if you are moving to another place totally might have to use
sd/usb and xfer or upload to drive, i have done that before too. 
might I add this only works if you had cache/log enabled I believe.