With the X Tesla does seem to have people over a barrel. Whilst we don't need the space either all the time, been able to take the entire extended family on road trips (remember those times??), and just the luxury of powered doors, space, and that windscreen means a Y would be a massive downgrade.
There is literally no other EVs around with the utility and space of the X, but asking £90k as the cheapest option is crazy, £64k was the starting price when we ordered in 2016!!
Hard to know what the OP should do, but a used 100D X would be my choice right now. Falling that get the deposit back and see what else comes to market in the next 6-12 months.