Where to stay in London when arriving at 10:45PM

I wouldn't count on getting the train out of Heathrow late at night. The last one leaves Heathrow just about midnight. By the time you've gotten off the plane, gone through passport control, and gotten your bags if you checked bags, there's little chance you'll make that train. And if your incoming flight is late, or you're seated in the back of the plane, or your flight arrives at the same time as a few other big planes so that passport control is backed up, well, you get the idea. If you miss the last train, then you're committed to an expensive cab ride to make it to your hotel. I'd just bite the bullet, stay at the Yotel in the airport, and take the Heathrow Connect the next morning. It originates at Heathrow, so no worries getting a seat, rush hour or otherwise. The Yotel is actually kind of cool; a cross between a Japanese capsule hotel and a first class plane pod. Check it out on Tripadvisor and see if it meets your requirements. Me, I've stayed there twice and wouldn't hesitate to do so again.

You will need to be at St. Pancras by 7am, so I would suggest going into London and staying so you won't have to deal with rush hour traffic going into London. If you stay near Heathrow you would have to leave around 5:30am to give yourself enought time to get to St. Pancras by 7am. You could stay at Comfort Inn.......http://www.comfortinnandsuiteskingscross.co.uk/hotels_near_st_pancras_station.htm ~~~~~ it's only a few minute walk to St. Pancras. I know that there is a N9 Nightbus which goes into London from midnight to early morning...but I don't know anything else about it.

If the thought of "yotel" bothers you (i wouldnt choose that- claustrophobia) there are other good large "chain" hotels all around heathrow and a few (i recall) connected to the terminals

I did that same schedule in 2009 I stayed at the Sheraton by the airport, and then took the tube to St Pancreas to catch the Eurostar. It was easy! The good part about catching the tube from Heathrow is its the first stop, so you will/should get a seat. The hard part is when you get off the train, you have to push and shove because you will be with the commuters. Go to Hotwire.com and you shoudl get a great hotel deal. I think i paid $67 for my Sheraton.

At Heathrow, everything depends on which terminal you are in. Recommendations to stay at Such-and-Such are problematic, if not useless, if it isn't at your terminal My recommendation: Pay for a cab or hire a car and driver to get you into London to a hotel near St Pancras. In the morning, you won't have to worry about delays getting into the city, etc. Stuff happens. St Pancras and King's Cross station are only a few hundred yard apart. A hotel near either should work. I'm staying at a Premier Inn at King's Cross next month, before catching a train the next morning.

If it were me I'd plan on getting into Kings X/St Pancras area on the night you arrive and find somewhere to stay.
Not sure what day you arrive but we have a Bank Holiday weekend coming up and the transportation options, closures etc could have an impact on anything you plan.

I stay at the Crestfield Hotel near St. Pancras. It is inexpensive and convenient to the trains. It's best to have a reservation. You really don't want to be looking for a room at midnight. There are many other hotels in that area, at a range of rates.

If you decide to stay near Heathrow; the Premier Inn Bath Road is great. I paid 39 GBP this month and it was a very nice clean hotel. I can highly recommend it.

I'd never heard of Yotel before reading this thread, but after viewing their website I really want to stay in one. The one in NYC seems very cool. The one at Heathrow looks like an ultra-luxury train cabin.

I second J.C.'s suggestion. Yes, a taxi to a hotel near St Pancras/KC will cost maybe $75, but the next morning you can roll out of bed and walk across the street to catch the Eurostar without worry or hassle. Keep in mind that the last Heathrow Express train leaves Heathrow shortly before midnight. If you have bought a ticket online and if you do not have to wait for checked baggage, you could probably make it...but even so, you wouldn't save that much over a taxi from heathrow to your hotel near St Pancras.