Access /home/user-data via Filezilla

As my Linux is a bit rusty please allow me a silly question.

I am about to perform a long-overdue upgrade from V57a / 18.04 to V71 / 22.04. So I need to make a backup first and get these files off the current instance and then back onto the new instance, via a (Windows) PC.

I run into the problem that when I use Filezilla (keyfile login) I am only able to log in as user ubuntu. And this user does not have access to /home/user-data. Using Putty one would sudo up and get access but that is (afaics) impossible in SFTP.

My question, is the best way to move the backup files to and from a directory that user ubuntu can touch, or are there currently better ways to move these files to and from a PC to a MIAB instance?

I personally use the pre-installed webmin. It allows me to easily pack and download data.

This seems like a limitation of your software, Filezilla.

Why not SSH in and copy/move the files to a directory that the user ubuntu can access?

Or even better, why not rsync directly to the new VPS rather than download and upload to/from your PC?

Windows does have a terminal these days, no?