I've never packed my rear panniers to capacity. However, my wife who has the Packer Plus style, packs her panniers pretty full. She does not use front panniers. It may be a little hard to see, but she has room to stow her running shoes in the space. She also uses a Tubus Cargo rack.
I have a short torso in proportion to my leg length. The top tubes on LHT's are really long. This makes me feel a little more stretched out than I'd like, but it is still a pretty good fit. I've put several thousand miles on the bike with no real problems.
You might want to warn your wife that touring is addictive. Have fun!