I'd suggest checking the recent actual election results (previous GE, locals and any by-elections), then checking a few different tools to see the predictions, and kind of taking the average of that.
Of course, you can always donate money and/or campaign somewhere other than where you live. I'm in a 100% Labour hold, according to electoral calculus, so I've been doorknocking elsewhere.
Cool, well now the link's working, and not to sound like a looping spambot, but I wouldn't use this MRP to decide your vote. The MRPs have such huge variance this time because of the historic size of the swing from the Tories to Labour (and everyone else) that it's really difficult to be accurate with this analysis.