If they're closing your depot then presumably they cannot force you to relocate to another base elsewhere? I would have thought that might give you an 'out' if you were to hang on until the end, as at that point they have chosen to close down your place of work rather than you choosing to leave?
That again would depend on what's in the specific employment contract here, and (if it got to a tribunal) what that tribunal considered 'reasonable'.
And presumably if a depot is being closed (or moved) there's some negotiations going on about what will happen - if it's Stagecoach, then presume we're talking a unionised workplace?
Are all current routes moving to a different depot/s, or are some routes being transferred to a different operator? If the latter then there might just be a case for 'TUPE' transfer to new operator, although you generally have to work a majority of your working time on the route / group of routes that's being transferred, so this is only likely to apply if there's separate driver rotas for different routes (as often happens in London.)
At some points in time, a depot closure might lead to driver redundancies - are they expecting that here? Or are they short enough of drivers to want to hang on to everyone? They may be seeking volunteers for redundancy, and with less than 2 years' service, there's no statutory redundancy pay, so writing off the training bond of newer drivers may be an option company is prepared to go for rather than paying redundancy to long service drivers.
Although there's no obligation on employers to offer voluntary redundancy, or to give redundancy to anyone who volunteers (and there are a few employers out there - I trust not in this case - who will not give redundancy but make life difficult for anyone who does volunteer.)
And it depends how far the move is (I'm not expecting the OP to go in to specifics / identify their location here.) A mile or so away is probably not going to make a lot of difference.
Some employment contracts (not just bus drivers') have a clause that you can be expected to work at any location in X county, or within Y miles of the work base you're taken on at. Some will include a negotiated 'disturbance allowance' (or whatever it's called locally) where you get an additional payment of X amount for 6 months (or something) per mile per week for the distance between old and new base.
I believe there is some case law on this - expecting someone to move to a work base that's an 'unreasonable' distance away can sometimes count as redundancy.
But what's 'reasonable' (as far as the law is concerned) will take specific circumstances in to account. From memory, something like expecting a senior manager to move to a base 10 miles or so away is probably OK, expecting the same from the office cleaner who's employed for an hour a day and would have to catch 3 buses each way probably isn't reasonable.
All of the above subject to the disclaimer that I am not a lawyer or HR person, and it's a while since I have been a trade union rep...