Don't do anything different except keep a close eye on how often you water (less if the tree does seem to stop growing, a lot less if it actually does lose its leaves as would be expected in the north). Certainly you don't have to worry about it being too cold, or freezing winds, etc. In fact, if you can at least keep it on the north side of the house to get any smidges to cooler air it will thank you for that.

Seriously resist the urge to do a late autumn repot. Some maples show their gratitude by bursting into new leaves and keeping them over the winter - then looking astonished when spring arrives. Mid autumn is usually fine. Root growth continues over the winter, though slowly.

All my maples live out over winter in regular rainfalls and occasional frosts down to -5C. I start by moving them from summer dappled light to full light in mid autumn so they can colour up, and ease back on the water, and feeding.

That said - this area has fairly high humidity and a mild range of temperatures. If you experience high 90s to 100+ you'll definitely need to take that into account in your management programme. For example pebble trays with water to increase humidity and slow down transpiration, plus shade cloth or use the dappled light under older trees with reasonably open canopies.

The main thing I need to watch for over winter is actually dryness. Make a point to check the weight of each pot if you've had a run of dry days, windy spells, or frost then sun. It can be surprising just how quickly they can dry out. Plunge, then drain.

Over winter is also a good time to weed the pots before the spring surge. Land cress and Oxalis species know nothing about dormancy. Nor do Violas.

If birds are plentiful in your area then you may need to consider protecting any moss plantings in your pots in early spring. If your trees aren't tied into the pot then both moss and tree can disappear under the bench in seconds. A suitable netting cover can help - but some birds don't mind burrowing...

You should have no problem with Trident Maple in your area. It's one of the maple species recommended for warm climates, offering some bright fall color in locations that don't have a lot of it! ;-)

I don't know if your tree will need a cold, dormant period as most deciduous trees do. I have read somewhere (and this sounds crazy) that you can store your tree in a fridge for the winter to simulate the cold weather. What I read was that since the tree is dormant during that period it doesn't need light or water. It's dormant. :)

Now I've never done this and would be hesitant to do so, but I did read it on another bonsai forum frequented by very experienced people.

Hope that helps.
Ed

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Lots of weird "stuff" in my fridge (some I can't even remember what they started out as LOL)but I think I'd draw the line on Bonsai Maples Trees in there!!! grin... But it's a good point made about moving them to reduced bright sun, and plan watering by hefting the planter. Thanks to all for the good suggestions and advice. Gloria