Hey guys, thanks for all the advice,
I’m pleased you mentioned about Leiðarendi cave, as that was one I thought was more open. I’ve now seen pictures of people sliding in down what looks like a snow-slide to get in during winter, so will avoid that one at all costs! It is a shame, because the pictures inside of it look stunning.
I think, considering my budget, a trip into Viðgelmir will be best, although I have been informed by the guides there that it will not open until June. Even so, the fact it is ten metres tall throughout most of it, and requires no crawling, means I think it will be worth the wait. I intend on taking the standard tour, and if that is comfortable, then maybe taking the extended one after.
Of course, the Into the Volcano tour inside Þríhnjúkagígur has enormous appeal to me, and I don’t think that, in a space that large, I should have any trouble with feeling crammed in! It is now a solid part of my summer plans, I can’t wait, just need to save a little to fit it in.
Thanks for getting back to me on this - I am fascinated with the volcanism and geology of Iceland, so didn’t want to miss out on a unique and special experiences just because of a slight phobia. Its good to know that every option is not closed off to me