This will require supports but I made it easy for you. I added a half circle at the bottom where the opening is, this is by design, its not needed for the model but it does block tree supports with touching buildplate option from filling the inside cavity, some will enter but are easily removed, or you can leave them inside, its up to you. The ones that enter are needed to make the print work.

I added the rock to make the model more upright from the original.

Plus it gives it a cool look, like he is tired from the work on the rock.

Recommend outdoor material if planning on using outside. I sized this to be what I found online as a standard gnome size and can be printed on a normal sized printer.

PLA would work for shaded outdoor areas but why take the chance print in ASA, PETG, or ABS I suppose.

I printed this in Iemai rainbow PETG with a .4mm nozzle at .2mm layers with a .2 initial layer, 3 walls and 5 top and bottom 15% infill with 15% overlap . Makes a strong print.

I recommend filling with sand, or BB's. Less chance of the dog running off with it or it getting blown around the yard.

Scaling - you could scale this, make sure to scale them both, I don't recommend that.