If you have a south or west facing window you sure can over winter them inside. I have been doing it for more years than I can remember. There are other ways to save them for the next year too, but I'll get into that in a bit. First here is what I do. I try to get the shortest bushiest ones.I remove all the flowers and buds, and cut them back, to a leaf, to make a nicely shaped plant. I pot them up and put them in my south facing window. I only fertilize once or twice during the winter with diluted strength and only water when they are dry. When they get tall shoots during the winter, I cut them back. Every time you cut them back they make new shoots and I want this so I can take cuttings in the spring. I got 41 cuttings off of 4 plants this spring. If you have a cold cellar or a place that is just above freezing you can store them there for the winter and let them go dormant or you can hang them upside down, bare root, in a paper bag(punch holes in the bag) For both these 2 you need a cool dry dark place that is just above freezing. In the spring, pot up the bare roots--the rest is for both ways. Move into indirect light and give a little water. Not too much--they have no feeder roots yet. Gradually increase the water and move more and more into direct sunlight and only then when they are growing well give them a mild 1/4 strength fertilizer I hope this helps

If it's in a fully enclosed porch, that helps. If it's warmer in there during the day, that helps. But it can also help if you get yourself some bubble wrap and wrap the pot a few times. It's kind of the easiest and fastest ways to get a little extra insulation on a pot in the porch if you can't do more serious stuff. If the pot is small enough to fit in a cooler, that works well too- think of the styrofoam caps folks sometimes use on rose bushes to overwinter. If you get box food delivery service that has insulation in the box, that insulation works well too. Yes, you should water. But not a lot. You don't want the dirt to go bone dry, but you don't want it wet either. The plants are dormant and so don't really need water themselves, but the dirt still should be a bit moist. And pots seem to want to stay damp longer when it's cold out so you might not need to water much at all depending.

Whatever you do, don't leave it in the pot outside. I did the same thing as you last summer and grew a few silver maples from seeds. I left them outside and none of them made it through the winter. In Chicago where I live we did have a very cold, snowy winter last winter, so I'm sure that was part of it, but having the plant freeze solid for a period of time didn't work out so well for me

This tree is very hardy but seedlings are less hardy than larger specimens and roots are much less hardy than tops - with new roots being less hardy than old roots. Covering the pots with loose material like mulch or sand may be adequate in your area. Do not attempt to overwinter in a significantly heated area. If the roots are getting crowded in the existing containers it would probably be preferable to bump them up now instead of in spring - unless the roots have to be worked on quite a bit to get them opened up and untangled, in which case it could be better to attack them at the end of winter. Do not grow on with bound-up (circling etc.) roots, correct root deformities caused by under-potting when moving to larger pots or planting out in their final positions.