Hi auk. I’ve taken the advice of everyone on board. I haven’t however bought the tree to stay in someone elses garden the entire time.
Trees belong outdoors. If you want something indoors, get a houseplant.
Stay long enough on this forum, use the search function and search for elms, Find how many posts are from new people, keeping their dying elms indoors and you will understand the scepticism.
Problem is that you want us to tell you what you want to hear and that the plant can be kept indoors. Sorry, I'm not going to tell you something that''s not true.
Chances are that the tree will come back and live. But it will not thrive. For bonsai, to be able to work on them, you need trees in excellent condition.