With a strict botanical definition, 0m

If you use a commonly used botanical definition, trees are distinguishable from other plants in that they grow new rings each year. As soon as you only have one ring, it's technically not really a tree anymore. For instance, palm trees have a single disk, which is why we tell it's a "tree-like" plant rather than an actual tree.

And unfortunately, the same thing happens here with one single, hollow ring, so if they're pedantic, a botanist will tell you you cannot have trees with an hollow trunk.

But honestly, that's neither interesting for the common folk, nor as an answer to a question that just wants plants to grow. So we'll use the broader definition of "tree" : Something big, with a sturdy trunk going upwards that needs more than your fists to be cut down¹.

With the day-to-day definition

Since your tree cannot actually really grow like a tree, I suggest you look at bamboos. Indeed, they have a very similar structure to your proposal : A single ring with some reinforcement inside. The main difference is that the reinforcement is set at regular intervals for bamboos in the shape of disks. For your hollow tree, it's more chaotic but likely more "filled" at the same time. While its growth is quite different from regular trees², it can actually be an inspiration of how they can reach such heights.

^{A patch of Dendrocalamus Giganteus. By David Stang, from Wikimedia Commons}

As far as I know, the tallest bamboos live in the Dendrocalamus genus^{3, 4}, with height branching from 20 to 40 m and with a comparetively low 10 to 30 cm in diameter. So you can very reasonably set your expectations in those areas. If you add more internal structure, you'll likely be able to grow higher and -most importantly- wider. Higher fiber proportions and higher material density should also allow overall stronger trees⁵.

You likely won't get much wider trees because there's littlenot much evolutionary advantage in that : The canopy of leaves won't extend as much as a regular tree which allows more developped, fatter branches. It's a trade-off between winning sunlight dominance (by faster vertical growth) and a stronger structure allowing more sunlight at the end. Also, a larger hollow trunk is more likely to get the attention of animals and insects. Whether they are looking for shelter or to parasite the tree, they don't need to digcarve all yourtheir house anymore, mainly the exterior wall now. It can be nice to think about that too when designing your ecosystem as a whole. This can be also an impeding factor in how big your tree is.

^{1 : Contrary to what a famous video game can tell you :p.
2 : The bamboo's shoots acts a bit like a telescopic tube : Everything is already inside, ready to expand and grow leaves. See this video for a more visual demonstration (in French, but having watched it without sound it should be understandable enough)
3 : Source : https://en.wikipedia.org/wiki/Dendrocalamus_giganteus
4 : Source : https://bambubatu.com/genus-dendrocalamus-the-biggest-bamboos-of-all/
5 : Source : https://jwoodscience.springeropen.com/articles/10.1007/s10086-017-1687-3}