Certainly the landlord has every incentive to want to pin you down for another 1 year's commitment, but that is not required. Almost any US lease falls over to a "month to month" lease at the end of the term. I know you're concerned about the rent going up significantly if you do, but every rental I've ever had, the month-to-month rate remains the same as last year's lease (unless they affirmatively raise it).
I gather you've been renting for several years, re-signing a 1 year lease every year. The landlord is unlikely to have a problem with breaking a lease near the end of the lease; after all, the lease has served its purpose by assuring that you aren't a short term tenant. Since you have a convivial relationship with the landlord, the landlord is likely to let you out of it without a hassle.
Given your plans, signing another 1-year lease would be madness. You are committing to guarantee the rent for the next year on the unit. Landlords have a duty to mitigate your losses, i.e. find another tenant, and whatever the other tenant pays reduces your obligation by that much (hopefully 100%) -- but if the new tenant is slow to find or doesn't work out, the landlord's losses are on you. Functionally, you are committing to pay rent for a whole 'nother year. Don't do that unless you can really afford that.
I get the power of habit, and it's been your habit to sign new leases every year. Stop.
I hear you're worried about a month-to-month tenancy being significantly more expensive. You need to check your state's rental laws; but that sounds very unusual. On the other hand, it would not surprise me for a landlord to offer a lease with different monthly rates, including a month-to-month lease (a contradiction of terms) at unreasonable prices; the purpose being to goad you into signing another year lease, or get you to sign away your rights under state or local law. If you're under rent control and the landlord gets you to consent to an otherwise illegal rent increase, then you lost your rights. But if you can't escape that clause, breaking a lease is likely to cost you at least 1 month's and probably 2-3 month's rent, and possibly the full twelve... so consider that in perspective and balance your risk accordingly.