Checking how much is on it is easy if you have the wallet address.  Just go to any blockchain explorer that supports dogecoin and search for your wallet address.  This is the one I use:  
[https://bitinfocharts.com/dogecoin/](https://bitinfocharts.com/dogecoin/)

While looking for a completely different file, I came across an old doge wallet from about 5 years ago. It wasn't much at the time - but probably a couple hundred pounds now. I'm fairly sure I remember the password on it, but what's the best way to access it and check how much is in it?

Found an old wallet, and I'm pretty sure I remember the password - how to access?