Keep all your IMAGES and the CATALOG on one 'Master External' drive. Use it as your "at-home" and "take-away" working drive.
Create an exact 'mirrored' copy (or two!) as your Backup Drive and keep it at-home and up-to-date by synching from your 'Master' drive on a regular basis.
You can load your catalog from the Master External Drive on any computer with Lightroom installed.
Use software to create your 'mirrored' backups (Not Lightroom)
Thanks for your reply. This seems like a good idea that might try. My main issue with going this route is that I don't want an exact mirror copy of my main drive as the amount of images is huge and would not fit on a slim portable drive, I would have to carry around a huge full size external drive and I just refuse to start living my life that way lol. I actually just want to choose the 1 or 2 main folders in my main drive where my clients' images are most likely to be and which I might most likely need at a moment's notice and just carry that around in a little slim 2T drive. Plus your solution feels more like a workaround and I just want Lightroom to do this natively exactly as I need it - lol again.... But once again, I appreciate your input and in the end your solution might actually be my only option, so I thank you.
So- a slim portable drive- "Smart Previews" is the answer.
When at home, in the Master Lightroom catalog library, Select one or more folders of images in the folder panel, go the Menu > File > Export as catalog.
Export the catalog to the small travel drive, choosing to export Smart Previews only. You can do development work on these Smart Previews-
When back home open your Master catalog on your 'Home' drive and go the Menu > File > Import from another catalog, and choose to import from the catalog on the travel drive.
I have just tried one folder of images, and exported a catalog to a USB flashdrive. This worked OK. When I imported from the USB catalog, any images I had developed came back to my master catalog by creating virtual copies, so no original edits are lost.
Try this method with just a few images selected, you will soon appreciate the 'export catalog' functions.
The way I would probably do this is to keep the files I am currently working on on the internal drive of the computer. Older source images are kept in the external drive. The LR catalog is on the internal HD. When I am done with the current images, they are exported to JPG with the edits applied. The source images are then transferred to the external drive. This file move can be done inside of LR or done outside then relinked.
Source image files can only exist in one place as far as the catalog goes. Images stored on the external drive will be available when the drive is attached and not available when detached.
The exported JPG files can be stored on the internal drive for quick presentations. Delete them as space is needed. Recreate them as desired from the external drive.
Using external drives for older images that are not needed frequently is a common scenario for LR.