This seems the most simple and cost effective method since I have long runs of vga cable and I could just use the DVI to VGA adaptor at the laptop like you described and the rest is business as usual thanks guys for the help.
It may not be so easy. Because it is a physically large connector, DVI outputs are a bit uncommon for laptops, so have they specifically stated that the laptop has a DVI output? And if so, have they stated what form of DVI?
There are multiple variations of DVI including DVI-A (analog), DVI-D (digital) and DVI-I (analog and digital). There are also single link and dual link variations. The dual link variation is uncommon and a laptop would almost certainly be single link, but it may be DVI-A, DVI-D or DVI-I. DVI-A can be adapted and treated like VGA/RGBHV while DVI-D can typically be adapted and treated like HDMI (but without audio, Ethernet, etc.). DVI may be able to be approached wither way. If the laptop is DVI-A or DVI-I out then what you propose may work, but if it is DVI-D out then it will not work.
Also, when addressing VGA you need to consider factors like the resolution, refresh rate, cable quality, amplification in DAs used, etc. Just because something works in a specific application is of limited relevance to others unless all the factors involved are the same.
Also consider that if you DA at the stage you may be amplifying any noise and signal degradation picked up from the first 100' run.