Id say your about 40 mins away looking at the map although like you say your on the wrong side of Lincoln to be honest.
I travel with my brother too so generally have 2 spare seats on this side. Im thinking about Northampton, its only about an hour away for me. Straight down the A1 so thats not a problem, not 100% sure I can make the date though, will have to get back to you on that one.
Thanks