Lamontagne is a resident of Manchester, so he does live in the 1st. His name is mentioned as a possible Senate primary challenger to Ayotte next year.
Ovide Lamontagne has been losing statewide races (either in the primary or the general) for years, so, if Gunita ends up resigning (which he has vowed not to do, but one never knows what tomorrow might bring), it would be wise for Lamontagne to run in the NH-01, which is a few points more Republican than the state as a whole and where he wouldn’t be facing an incumbent that already beat him in a GOP Senate primary. Yes, Lamontagne is quite a bit more conservative than the average NH Republican, but he can win a special election in the NH-01 and then use incumbency (and, hopefully, some coattails from the GOP presidential candidate) to win reelection in 2016.