If on a yearly lease, the lease would "roll over" to the new owner (you) until it would normally expire. 

If you want to invest the 401k money, or part of it, into real estate, then setting up a self directed IRA and rollover the old 401k plan is the way to go.

Your business would start a 401k and then it would roll over prior funds from an IRA or other 401k.

Don't call between 10 and 10: 30, 12:00 to 1:00 or 3 to 3:30, they are in the lunch room with their phone on roll over!

If you are looking to flip houses your best bet may be to open a Rollover as Business Startup (ROBS) 401k as it will not subject the flipping to UBIT.

Rollover tenants for the most part, have to either be evicted or re-trained to be good tenants.

At the end of 5 years, if you have been making your payments, lenders essentially offer you to roll over to a new 5 year term with however long is left in your amortization, but at prevailing market rates. 

@John Wanberg Self Directed IRA's and Solo 401Ks allow you to roll over your 401k/IRA into a trust account or LLC and use the funds to invest in real estate (or gold bars for that matter).  

I think you biggest risk, is the market changes or your bank changes and they tell you that they aren't going to rollover your loan.  

You know other investors, contractors, pro's of all stripes (hundreds just her on BP).You're not a little pedestrian who they can roll over.