Thank you all for your comments. They are greatly appreciated.
The tree will be planted at an institution where there are ground staff, enough room and close enough to buildings I am told.
As for the whole size issue, the reason I stated allegedly is because I was sceptical of a tree being such a size at that age. After looking at several sites it seems this is so.
I attach the link an example. This link is primary for Gary Hobson and blairs so they can understand where I am coming from. Likewise if of course I have made a mistake please say. The site I am no way connected with, nor endorse and is only highlighted as a reference.
<span class="Apple-style-span" style="font-family: 'lucida grande', tahoma, verdana, arial, sans-serif; font-size: 11px; line-height: 14px;"><a style="cursor: pointer; color: #3b5998; text-decoration: none;" href="http://www.mailordertrees.co.uk/Quercus+rubra+%28Red+Oak+Tree%29/0_caaa102_caaa136/PRAA353.htm" rel="nofollow nofollow" target="_blank">http://www.mailordertrees.co.uk/Quercus+rubra+%28Red+Oak+Tree%29/0_caaa102_caaa136/PRAA353.htm</a>
Otherwise judging by these comments I can plant the tree soon as long as watering is available. If I can wait until Septmeber it would be better. Great.