not sure there is a perfect vehicle.
Our first van was 4.8m but fully equipped and we had 1500+ nights away, wintering and 4 mth trips. Was amazingly reliable and well made and taught us a lot. Deffo spacious enough.
Our current van is *tiny* but we've been away for 6w trips, mainly wild camping, and its fine, but compromised obviously. But as its a daily car as well, it works well. Its a "campervan" not a "motorhome" and to us there is a difference. Suiting us well for its purpose and current usage.
We like small and stealthy for the sort of trips we do, but the next van will be used more and longer

and will need to be more of a motorhome than campervan.
next van we'll build
MWB 5.4m 3.5t
Internal garage for 2x bikes, and 2x snowboards at the same time(heated). And gear/armour/helmets
Double bed
dual fuel heating.
Winterised, onboard water, strong insulation
L shaped lounge (convertible to U).
Stealthy
Solar, batteries, and clever bespoke electrics (v2 on current design)
Full bespoke wetroom/shower room/toilet
Hot water, kitchen sink, fridge
Water/waste/loo/fuel capacity for 1week wild, (inc 6x showers) and 3mths with easy fuel and "aires".
"Professional conversion" standard (with better spec)
There are a few unique design decisions we've made and not seen on any other van - so we're either genius or stupid, not sure yet! Plans coming on but it'll probably be a 2021 project....
Plans being designed at the moment to determine if its feasible - and at the stage of working out (and designing out) all the "joints" to make them simpler and DIYable. Thing is, I hate CAD so designing it in PowerPoint lol (more techie than van v1 that was in my head only!!)