You can buy the DVD version from Amazon.
looking for the upgrade DVD version of Lightroom 6
Adobe can't point you in the right direction because Adobe does not sell a DVD version of Lightroom 6.
You might be able to find it at Amazon or B&H.
I am often on location and out of reach of the Cloud
Lightroom 6 and Lightroom CC run properly when there is no internet access. These are not cloud applications, they run on your computer. Lightroom CC needs to use the internet once a month to make sure your subscription is paid.
Lightroom 6 and Lightroom CC run properly when there is no internet access.
Ahem, theoretically. The current version of LR 6 / CC has a bug that makes the program unstable or even makes it crash when there's no Internet connection available. The problem is acknowledged and should be fixed in version 6.1.