I had a similar 'plight' with a design I was creating for a very large model of a bespoke hospitality (tensile/inflatable) structure being built on the beach at Cannes - the model was constructed in SKP to show a beautiful pitch render (to the MS client) via Lightup, as well as serve as technical layouts, construction details, and work-in-progress sign-off scamps in Layout.
The necessary additional detail/model (including glowing inflatable cell-structure) size was killing my renders (and my soon to be updated PC), so I came to the state of breaking the model down and 'sub-render' (eg the exhibition zone) elements.
Sketchup & Lightup work brilliantly - it is just the scale of my designs that sometimes get in the way!!
I would concur and suggest 'pretty house' and 'real house' models! There are limits with all of this.
Good luck with it!