Blueman's post about pausing your account is absolutely correct. The only thing I'd add is that you can only use the pause feature once per rolling calendar year, unless you're a snowbird who maintains multiple residences.
Will you be between homes for this 3-4 month period? If so, I'd strongly recommend you pause the account (as former customer promotions can always change, and if you cancel, you'd be out $50 to restart anyway - in addition to losing your current HD-DVR).
If you're going to be moving straight from your old place to your new, I would suggest the following instead.
If I had to guess, you're paying something like $101/mo before taxes (assuming you have your locals and no warranty). If you don't want to give up your equipment, you could drop your programming to, say, DISHFamily with no locals and keep just your 622.
Then, use the DISHMover program to get a new dish installed at your new place. (Actually, I'd recommend making the programming changes after scheduling the Mover order. This way, you'll get the 1000.2/1000+ dish you'll need later installed for free as part of the Mover's.)
This way, you could return the 211 (which, with the account status you mentioned, should not be a big problem to get back for $0 after mail-in bonus on DIU). You'd just have $19.99 for DISHFamily and $5.98 for the DVR service fee (you don't pay that now because you have AEP).
It's a little more expensive than using DISHPause, but you'd have *some* TV service, plus you'd keep your DVR while reducing your monthly bill by about $70-75 while you get settled. There is a one-time $5 fee anytime you downgrade programming, but that's not a big deal, I would imagine.
Then, when you're ready, you could kick back up to the AEP+HD, and do the DIU for another 211 (or even 622/722, if you wanted - though neither would be free after mail-in bonus).
Hope this helps - and congrats on the new home.