Time to read David’s fine comparison of S to S2 again.
When I first read this review years ago, I didn’t want to like the new S as my S2 was only two years old, and I didn’t want to spend another huge amount of money. Reading the review now makes it more enticing, but especially so if you never want to leave CCD
http://www.reddotforum.com/content.php/279-Photokina-2012-Day-2-The-Leica-S-(Part-1)?page=2
With your preference for CCD you can easily justify the S with this trade in. However, if I were to to this I would trade in my old Pentax 6×7 not my S2.
I would try and sell my S2 on my own. Or use it as a backup. In 4 years of pretty hard use, I never had a glitch with my S2, other than the dimming top display they fixed for free and kindly provided a loaner. So I never lost a shoot. Net I really never needed a backup camera. So if it were me I’d sell. You may feel differently.
Am I helping you here? After your tough winter, you deserve a nice fresh S.
Jack