There won't be a significant range boost until they switch to the 4680 cells, probably two years away for the 3. The 520 mile Plaid+ is relying on the 4680s, that's why it's been moved out until next year. The Cybertruck and Semi are also dependent on the 4680s, they will have to ramp up production to meet the needs of those three products before they can switch the 3 and the Y over. Panasonic said that they think they can improve the 2170s by 5% per year so there could be a small boost to the 3 before the switch to 4680s but I wouldn't hold off a purchase for a lousy 5%.
That said there is no need to wait for a longer range 3, the range of the current model is enough. When road tripping all you need is a usable 200 miles of range, in good weather you should be able to get close to 300 miles if you don't drive like a maniac. The limiting factor on a road trip isn't the battery size it's the size of your bladder. Superchargers are plentiful and they are building more of them every day. Having to stop every two or three hours for a 15 minute charge isn't a chore. You stop, plug in, go to the bathroom and maybe grab a snack and then you are on your way. Pre pandemic we did 300-450 mile day trips every weekend, we didn't spend anymore time on our stops then we did when I had an gas car. As I said it's bladder size that limits how far you can go, when we needed to go to the bathroom we used gas stations when I had a gas car, now we do it at Superchargers. At a gas station you have to serialize fueling and peeing because you can't legally walk away from a car that's getting gas. The process was fill the tank, move the car and then go to the bathroom. At a Supercharger you can fuel and pee in parallel because the electrons aren't going to spill on the ground and catch fire. The bottom line is that the amount of time spent at the stop is about the same.
To get an idea about how hard or easy it is to road trip in a Tesla I recommend that you look at the Supercharger Map,
Use the interactive Find Us map to locate Tesla charging stations, service centers, galleries and stores on the go.
www.tesla.com
Search for your region and look at all of the places that you would like to drive to. What you'll see is that you never need to drive 500 miles between charges, if you can drive a worry free 200 miles that's all you need.