It takes an hour to build the box. A bit longer than that to do the initial load of updates, then do the restore overnight whilst I sleep. Next morning, I have a box ready to go. (minus some support programs that I discover I'm missing as time goes by and I re-add them.
Someday, I'm actually going to be smart and keep an accurate list of the other packages I install over time. Never have been able to really manage that because I'm lazy.
BTW, using backintime makes it really easy to make a backup for offsite storage. I hook up the external drive for offsite backup, umount /backup, then mount the drive to /backup. Since I run a full backup every night, the next morning I'll umount /backup, mount the original /backup device, and I'm ready to go.
Here's my /home and /backup partition. As you can see, /home is a 1.8TB drive that has just shy of 1TB used. The backup drive is 4.6TB and has about 2.4TB used.
$ df -h | egrep 'home|backup' /dev/mapper/home-zhome 1.8T 755G 987G 44% /home /dev/sdd1 4.6T 2.0T 2.4T 47% /backup
As I said, I do full daily backups. Because of the way backintime works, (using rsync and hardlinks) here is how many full backups exist... You'll note that each directory name below is date-stamped, so I have backups going back to 2015 on this drive.
$ ls /backup/backintime/xxxx.xxxx.net/root/1 20151231-030001-479 20161231-030001-690 20170731-030001-645 20180228-030001-140 20180525-030002-223 20160630-030001-190 20170131-030001-719 20170831-030002-690 20180331-030014-332 20180527-030033-789 20160731-030001-130 20170228-030001-368 20170930-030001-293 20180430-030001-556 20180528-030002-318 20160831-030002-520 20170331-030001-884 20171031-030001-309 20180513-030002-355 20180529-030002-873 20160930-030014-168 20170430-030001-517 20171130-030002-668 20180520-030001-570 last_snapshot 20161031-030013-599 20170531-030033-108 20171231-030002-454 20180523-030002-233 20161130-030001-598 20170630-030001-860 20180131-030001-957 20180524-030001-319
You are a lot more methodical than I am.