Help Deciding Jesmond Dene or St. George's

If you are taking the train to Paris, Jesmond Dene would be handy to the St Pancras station. I probably wouldn't want to spend 5 nights in that area; one night is ok. If the other hotel is close to transportation it might be a better location.

I always stay at the Jesmond Dene, location is so convenient.
I'm a Sr. too and found I could walk to the British Museum, hop the tube or bus when needed.

Jesmond Dene is just across the street from St Pancras Station (Eurostar to Paris). That's the main reason we're staying there in June.

We stayed in both the Victoria Station/Pimlico area (Luna Simone, which we loved) and near Kings Cross at the Jesmond Dene on two separate visits to London 3 years ago. I would absolutely stay in the Victoria/Pimlico neighborhood again -- transportation everywhere was super convenient, and the neighborhood was great. There were lots of restaurant choices, and we really liked the vibe of the neighborhood. We did NOT enjoy the Kings Cross neighborhood at all. It felt rougher, much less inviting. It's more of a "passing through" and young adults hanging out on the street kind of feel. (We're middle aged, btw.) We also weren't thrilled with the Jesmond Dene (although I've read the rooms vary a great deal -- ours in the basement wasn't super). If you were only in London 1 night and then headed on the Eurostar, I could see the appeal of staying near the station. But since you'll have 5 nights, I'd definitely recommend finding a more pleasant neighborhood in which to hang your hat, and using the tube to get around. It's also easy to get from Victoria Station to St Pancras via the tube. Or, depending on the day/time, you could even take a taxi from Victoria Station to St Pancras (we took a train from London to York on a Sunday morning, and for the 3 of us at that time of day, the taxi was reasonable and fast).

The Pimlico Tube stop looks closer for walking to/from St. George's but is only served by the Victoria line, so you may often need a Tube connection. Some days, you might walk the longer distance to/from Victoria station, where more bus and Tube lines meet.