Thank you.
Yes, I was thinking of Tent and Synmat on top of the rack, and everything else, including compact, lightweight bag or quilt in panniers, but that could go on top too. Not planning on a bar bag, though.
I'll see how I get on on at least one spring test run, and I could always get the rears (40-42L) if necessary; I'm sure I'll use the full set one day!