Dell Latitude rugged laptops

I have a small business where I'll need a solid rugged laptop in the field. I was looking at the specs and saw that the Rugged Latitude 5420 seems kind of outdated. Is Dell planning to release a new updated one anytime soon?

I have many holdbacks with this laptop, main one being lack of Thunderbolt support. And processors being 3yr old also kinda put me off.

I realize that with these rugged laptop, the customer is mainly paying for the rugged construction of the laptop. There aren't many competitors who make these rugged laptops other than Dell and Panasonic.

If I do go ahead with the 5420, Can you please tell me if I can upgrade the Harddrive, memory, processor, Wifi card, LTE/5G card myself?

I can find the Samsung evo 1TB nvme and memory for really cheap. And I can also get an intel wifi 6 card with Bluetooth 5.0 as opposed to wifi 5 card with Bluetooth 4.2 from dell.

I found the following prices (In Canadian):

Samsung 970 EVO Plus Series - 2Tb PCIe NVMe - M.2 Internal SSD (MZ-V7S2T0B/AM) - $430
HyperX Kingston 2666MHz DDR4 CL16 SODIMM Impact (HX426S16IBK2/64), 64GB Kit (2x32GB) - $384
WiFi 6 AX200 WiFi 802.11AX 2.4GHz 574Mbps or 5GHz 2.4Gbps(160MHz) with Bluetooth 5.0 - $26

Total: $840 from amazon.ca 

And 2tb nvme SSD, 32GB memory (instead of 64gb), Wifi 5 with bt 4.2 from Dell would cost me $3,613

I plan to keep the laptop for a long time and it just doesn't feel good spending almost $5000 on a laptop with 3yr old specs. 

What are your guys' thoughts? Should I pull the trigger and upgrade the laptop myself or wait for a refresh of the line-up? If its happening soon.