unfortunately for me >140.000 domains to block will crash the pihole web server in no time:
PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 75497472 bytes) in
/var/www/html/admin/scripts/pi-hole/php/data.php on line 581,
referer: http://pihole/admin/index.php?login
I was able to run ~400K domain with a 512MB/1CPU VPS from Vultr but the only problem I have seen was the loading time, it is going up over 1, 2 sometime 3 seconds wait before loading any webpage. Now i'm using my list with ~120K domains and is fine.