My question is regarding the non-extended, mid to high roof cargo vans' RWD or FWD winter performance.

There are videos comparing RWD, FWD,  AWD and 4x4,  but they are focused on non-van models. I don't have any prior experience with AWD or 4x4 and they are currently outside my budget.  I am looking to convert a cargo van with the aforementioned specs into a mobile photography/filmmaking studio. 

I realize non trail variants of Ford Transit and Ram Promaster are not built for extreme off-roading and overlanding. I am not trying to do anything extreme but am still uncertain about their RWD or FWD performance under inclement weather, snow-packed/icy/sandy or muddy roads, specially in combination with demanding situations like going uphill. I've found only scattered incomplete videos on this topic. 

Does upgrading the tires, installing lift kits and ensuring that the van is weighed down in the back enable a RWD or FWD van to handle the tough winter/muddy conditions or I am better off just going or waiting for an AWD van instead? 

I realize doing those upgrades doesn't mean I will get the equivalent 4x4 or AWD performance, but I would like to know if doing all that can actually create a vehicle that can handle most snowy, ice and blizzard conditions, muddy roads, sandy beach roads - in combination with going uphill under inclement weather.  Is a 4x4 or AWD strictly necessary for these situations?

Thanks for your advice.