Migrate a massive WordPress site (100GB+) using the free version of All-in-One WP Migration, which caps at 512MB by default.
Your 100GB site is not heavy; it's just a database and a folder of files. Go migrate it.
A workaround for the 100GB limit is to split your export into multiple archives. Here's how:
chown -R www-data:www-data uploads find uploads -type d -exec chmod 755 {} \; find uploads -type f -exec chmod 644 {} \;