I live in the Oklahoma panhandle and our extremes can be 114 F in the summer and - 20 F in the winter. I set VFT outside years ago in our hot sun and they were dead within 3 days. So now here is what I do with my Venus flytraps and they are healthy and big enough to eat medium sized crickets and large cockroaches. I bought some powerful LED full spectrum plant lights from Amazon so I can grow them indoors. I put them in an 8 inch pot not a terrarium as that fosters mold. I filled a spray bottle with distilled water and mist them several times a day. In the winter I use a mini fridge that is empty save for the plants set on number 1 setting which is 50 degrees then after 14 days reduce the setting to about 40 degrees. Oh I might add I put a thermometer in the fridge to get the exact temp. I put the whole pot in for 12 hours over night then take it out and put it back under the light 12 hours. It has worked great as I bought the plants last November and they are thriving and each year the traps get bigger. I guess to keep them outdoors you need to live further south than Northern Oklahoma. It doesn't harm them to over lap or hang out of a pot mine look like big ol bushes with so many traps. Get a flower pot tray to put under it and keep it filled with an inch of distilled water. You can buy peat moss and put them in a large pot they get 8 inch roots so need a deep pot to flourish. I hope this is more helpful for you to grow them indoors.
