Should I rebook my flight to save $300?

That extra day is likely to exceed the $300 savings, so I'd say only do it if it's about extra time at destination.

Sunday probably wouldn't be as crowded as the Monday holiday but Andrea has a very good point in that you will be paying for one more night at the hotel, plus food, etc. So to reiterate, only do it if you really want one more day, because you probably won't safe much, if any money.

Simple answer: No.

The saving from rescheduling probably will pay for the extra day, but my current itinerary calls for three nights in London before joining the RS Best of Spain tour in Barcelona; so the extra day might not be incentive enough for me to rebook everything and concern about long line at Heathrow. So I likely will keep my current booking.

As a separate question I wonder if I should stick to the hotel I've booked near Farringdon Station; it's far away from most tourist attractions (with the exception of The British Museum) but Farringdon has great London tube connections (Circle and Elizabeth line). A hotel nears Victoria Station could be a good choice as its walking distance to both Buckingham and Westminster Abbey. Maybe I'm thinking too much since I will be in London for only 3 nights :)

Thanks everyone for your inputs.

Farringdon is also on the Thameslink line to Blackfriars and way beyond- a useful short cut to the Circle line for Westminster and Victoria.

Don't forget buses- the 55 to Oxford Circus, the 243 to Aldwych (for the Strand) and Waterloo (for the South Bank).

And a very short distance away, at Mount Pleasant, the 38 to Wellington Arch (for Buckingham Palace) and Victoria- so you see London when on the top deck of a bus rather than being on a tube train.

Route 17 (from Charterhouse Street- just south of Farringdon station) takes you to the Monument via St Paul's Cathedral- at the Monument you are within walking distance of the Tower of London and Tower Bridge.

I think it's not a bad location.

I’d do it. I’d much rather spend $300 for an extra night in London rather than a flight. I wouldn’t worry about the airport. Heathrow is always crowded. As long as the egates are working, you should get through quickly. The only particular thing you will want to do is to check transportation from the airport closer to your time of travel. Portions of the tube are frequently closed on bank holiday weekends for maintenance.

I too would rebook for an extra day in London even if the total cost for the extra night exceeds $300

I've decided to keep my Delta booking but changed my hotel to one near Waterloo station. Since after London I will be joining up with the Best of Spain in 14 Days Tour and to be followed up with another 4 nights in Paris; I think trip length is getting close to my limit.

While Farringdon has great train connections; it's not particularly convenient for walking to attractions I plan to visit (such as Buckingham Place change of guards, Westminster Abbey etc). The hotel near Waterloo is walking distance to these places and provides easy access to the river walkways for nice strolls. From Waterloo Station I can take Northern follow by Elizabeth Line to LHR. I do plan to ride some buses to get a great view of the street scene; and monitor the transportation systems for strikes or line closure. I think I'm all set for my trip; except the long ten-month wait :)

Thanks everyone again for your insight and suggestions, really appreciate it!

Last night it dawned on me that I didn't have to be stuck with the $300 eCredit after all. I simply canceled my original booking; use the eCredit Delta issued after cancellation to book a new booking (which is $300 cheaper with the new May 4 departure date). I avoided having to stuck with $300 eCredit by changing my returning flight from Comfort+ to Premium Select. I did have to pay a little extra in cash to make up for the difference; but it's totally worth it! Happy ending!

Looks like you found a good solution. More space for about the same amount of $$

I just rebooked to save $25.

but you do realize that according to the "cookie myth" repeatedly posted on here neither of us should have been able to do this... I mean "EVERYONE" knows that if you repeatedly search airfares the airlines track you and the fare only goes up. (which explains why I now have $475 in credits from rebooking the same trip .... my repeated searching has caused airfares to go up... OPPS Hmmm... LOL!

@ Carol

if you repeatedly search airfares the airlines track you and the fare only goes up.

I used to think this's an urban legend (or cyber legend). But in this day and age, with AI + cheap Cloud data storage + huge computing power, it's totally doable for businesses to track online flight search of individual (people like you and me) and price the airfare accordingly and dynamically. How else can one explain the airfares are cheaper right before and after my departure date :)

When I first asked the Delta representative if I could modify/change my booking and apply the $300 saving for a seat upgrade to my returning flight; I was told I couldn't use eCredit for seat upgrade since I'm modifying my reservation. After the call I had this lightbulb moment and ended doing what I mentioned in my post above. I know this is likely obvious and trivial to most people; but I have never had to change my booking in the past so it did take me some 'thinking' to realize this workaround :)