Investing heavenly in an MacBook Pro makes imho only sense if you plan to use it more often and not once in a year or so (like this planed workshop).
How heavy are you using your CPU on your MacPro? One idea could be going to the MacBook Pro 15 with maxed CPU und SSD Storage you are comfortable with. This would be the mobile solution and at home plugin at a external monitor with Thunderbolt 3 port and use the monitor as a hub for the needed peripherals. With the upcoming High Sierra OS update external graphics card support over Thunderbolt 3 will be available so more graphics power would not be the problem.
I have since one week the current MacBook Pro 13 with i7, 16 GB Ram und 512 GB SSD and it runs fast. Lightroom should be ok. Due performance reasons I switched to Capture One Pro and imagine editing feels as fast as on my desktop PC (6 core i7 Haawell-E, 32 GB RAM, Quadro M4000, multiple SSD drives on Eizo CS270 monitor). Sure in preview rendering or exporting the more power is used by Capture One but the little MBP13 doesn't look bad
For basic editing the more basic models are good enough. My laptop before Imgot the MBP13 had an i5 and 8 GB RAM (also one 13" one) and RAW editing in Lightroom, PS and Capture One runs fine (I have Sony a7ii uncompressed files around 42 MB and 24 Megapixels). Heavy filters or huge PS editing stuff can take a bit longer but for this I wouldn't buy a 13" laptop. For this a 15" one with the quad core CPUs should be the way to go (and if mobile usage is one requirement).