I've just started all this malarkey for my daughter and I know what you mean.
Some have S,M,L and others have No1 to No4.
My daughter has quite a medium to delicate hand whereas I've been told I've got hands like a slab so it's been an outside study to sort her out.
She has ended up with a Hammerli AP20 Pro due to weight and cost considerations but it comes with the Walther 3D grip in medium.
Now it's a little large for her, not that she realises as each minute she's seen me adjust something to perfect the fit in her hand (even down to twisting the pistol slightly in the grip as her natural raise has the end of the barrel pointing slightly to the left of centre and high).
That said my plan has always been to find something that is close to perfect fitting and the only option I've found after her placing Steyr's and FWB's in her hand is that sooner or later with any of them is that I might have to take the Dremmel to it.
My plan was to go slightly oversize and trim it to suit her hand if I had to which, in your remote situation, might be an option to consider.
Another thing I found though is that my local dealer was prepared to send me home with both M and S grips with a view to returning the one I didn't want and this might suit you to order the LP10 with both M and S on sale or return for the additional grip.
In fairness my dealer wasn't even going to add it on the price but he does know me know.
Hope this helps
Mark