The USA idea of growing a bonsai on a table in the living room is a by product of seeing those beautiful photos of the Tokonoma displays from Japan. What we in the USA forget, the Japanese tradition is to grow the tree outdoors, then just before the visitors to the home arrive, the tree is brought indoors, set on display. Then as soon as company leaves, before the dishes are done, the tree is put back outside. Those trees are not grown where they are displayed.
Solution to your problem. You can not change the light in your living room. Fine. Grow bonsai outdoors. You need at least 50 trees. Then each tree can spend a week in your living room, on display, and then be returned back outdoors to grow. The continuous rotation will prevent any one tree from being overly stressed by spending too much time indoors. Make sense? Otherwise, a plastic faux tree is the only viable solution for a low light setting. Some of the faux trees are quite nice, just have to dust them off once or twice a year.
Seriously, most outdoor grown trees can really only tolerate a couple days indoors before they begin to suffer distress. It would really be better if your tree collection was closer to 100 trees. You are in Pennsylvania, Winter would be a tough time to bring trees in. Do you have a basement? I have several hundred orchids and a few subtropical bonsai all under lights in the basement. I bring different plants up for display for a few days, then return them to the basement. It is possible to grow many sub-tropical trees under lights if you set up a proper under lights grow space.
In different areas I use cool white fluorescent shop lights - for lowest light intensity plants. Lamps are hung low so they are just about touching leaves of the plants.
400 watt High Pressure Sodium grow lamps - these throw tremendous amount of heat, but since the basement is unheated, in winter this is a benefit. They are hung about 24 inches above the leaves. Each will light a 3 foot by 3 foot area to equivalent of 25% sun outdoors. the outer limits of the area are a deeper level of shade.
8 tube High Output T5 fluorescent lamps 48 inch length. This uses roughly 400 watt and lights roughly 4 feet by 4 feet area to 25% of full sun. Throws less heat than the HPS, I like the color better too. I use 6000K lamps
1000 watt HPS, this only lights a 3 x 3 area at about 50% of full sun. I can grow my tallest trees and orchids under it. Some 4 and 5 foot tall orchids are under it (Sobralia can get that tall) and a few larger trees. (Ficus, Bougies).
All of these would be unacceptable in a living room, but work fine in the basement. Or if you have a spare bedroom or office, you could set up your grow area there. Then over the winter rotate different trees in and out of the grow area to your display area.
Hope this gives you an idea how to get around the problem?