Do you already own the Epson 600? It's a good one but the Canon I bought is limited to 8x11 on the bed, too. In my search I didn't find many scanners these days that go larger and they tend to cost a lot more. It wasn't a priority for me, but I didn't see many (even the 700/750 is that size).
I did scan some pictures without removing them from the pages but only when I couldn't get the pictures off the pages yet I could take the book apart. That worked fine although sometimes I put it on the bed twice with different orientations to get everything. In just one case did I have an album I couldn't get apart without destroying it and destroying it wasn't an option. That was painful--the scans turned out okay, but I had to rig a way to hold the book flat and in place on the bed with the top as closed as could be done. Doable but slowed things dramatically.
That took too long for me to want to go that route unless I absolutely had to. Those pictures (and the album) had better be worth it because it takes a long time to get them done. At first, I was reluctant to destroy the album in the process but I quickly decided that preserving the pictures was important but the album had to be expendable if necessary. After all, when you've got the scans you can make a new album/picture book for anyone who wants it--without the scans that's not possible.
Don't forget you also should get information about the pictures--if the albums have good labels you may be okay. Otherwise you need as much who, when and where info as can be supplied.
Good luck -- it's a daunting project but satisfying to get even some of it done.
Oh, yeah, for anyone who hasn't checked the blog, the whole 4-part series
is posted. I'm tied up at work and traveling a bit, but I still intend to post some examples and specifics on old picture scanning.