What I do in the spring and fall is move the pots out of my garage every morning (weather permiting) and drag them all back in every night. I know it is a giant pain, and the more you have the more of a pain it is. I do not know if this is a plausible option for your situation, but it works for me.
Windows block to much light and UV typically leading to weak leggy growth. Additionally, after being in a window the trees will need to be hardened off before they go into full sunlight or they will go into shock, plus other issues.
High intensity lighting it's an option, if you don't mind the cost, yet it causes issues much like the Windows do.
Good luck, I think this is going to be an issue for many people in many places this year.