VPN to a license server for mobile workers

I support a small office 2-3 engineers who use some pretty expensive and compute intensive cad applications (autocad / tekla). They want to share licenses - which is totally allowed by the SW vendor. This works well at the moment when all are in same office and both laptops are connected - one gets/relinquish from colleague by asking and acting. Laptops are only active when license is being moved, does not need to be permanent connection

Now they want to go mobile, but again for small number of workers 2-3.

SW vendor suggests leaving a small windows server running the license server on 24/7 on same network as local users.. Remote workers would then vpn to get or relinquish a license. At the moment the office only has exernaly hosted email and web - no website hosting or VPN stuff. What sort of extra network equipment would I need to host inbound VPN - maybe open some ports on there DSL/firewall - perhaps add an an extra device.

The other thing is to host in the cloud - AWS/Azure, my own license server and allow any of the office laptops to VPN to it to update license.

Any comments appreciated