Don't you have any backup tea at the back of the cupboard? The slightly weird tasting one that someone got you at Christmas? The Earl Gray you got for that person who came round once? The loose leaf ones you normally can't be bothered using?
What's wrong with Earl Grey? Insufficiently English? Just curious since I do love me some bergamot, and want to make sure I have appropriate supplies for UK house guests later this year. Are you guys "1st flush Darjeeling or gtfo"?
UK house guests will most likely be expecting an English Breakfast Tea, if you insist on buying fancy ones with posh names. We don't call it that, we just call it tea. There's a couple of stray 'lemon' or 'green' in that list but most of them are bog standard blends of black teas called 'tea'.
Be aware that you will have to get lucky to make a proper cup of tea. Most of them supply slightly different blends to different areas of the country depending on how hard the water is.
We trailed this a few years ago in the supermarket I worked at. The idea was you'd buy the jug and then just buy a new bag when you needed one. Save on plastic waste I assume, but it never caught on.