Suffer SVR for 5 months to sync up 2 part mortgage

nealo

Part 1 £85k, 1.95%, £447/month, Ends 30/4/2025
Part 2 £120k, 1.94%, £629/month, Ends 30/9/2025

Currently the Chelsea SVR is 8.24% ( 3% higher than BOE)
If BOE came down to 4.75 (by April) and SVR went to 7.74 then a spreadsheet I downloaded reckoned the 447 would jump to 706.  so 259 more per month.
For 5 months that would be roughly £1250. 
Just to sync it up and then lock in for 2 years. 
Which we would probably look to move house and downsize slightly after.

If I just extended by another 2 years on both, I might get a 5% deal on the 1st part, and maybe 4% on the 2nd part.

Trying to wrap my brain around if locking all 200k in at the (most likely) lower 09/2025 rate would save the same or more....

Hoenir

Why the desire/need to sync?  Let the two loans run their natural course.  Overpay the one with higher rate of interest.