Thanks for all the feedback.
Following some leads presented above it turns out Delaware, as a no sales tax state, is a haven for fine art storage
. The rate I found was $3.50/ sq ft/ month with a $100/ month minimum. The .wife is thinking of keeping the large painting and hanging it in the small apt. building we own and currently live in. There is a piece of wall space on the 3rd floor that is pretty inaccessible where the painting would b protected. The she will sell others.
But we are not yet settled on a plan and may all check out local galleries.
Thanks for all the help.